Gonadotrophic, prolactin, corticosterone, and gonadal hormones levels over 15 months in Giant Amazon River Turtles - Podocnemis expansa (Schweigger, 1812) (Testudines: Podocnemididae), in captive conditions / Gonadotrofinas, prolactina, corticosterona, e as hormonas sexuais durante 15 meses de Tartarugas da Amazônia - Podocnemis expansa (Schweigger, 1812) (Testudines: Podocnemididae), em condições de cativeiro

Abstract In order to achieve successful captive breeding the Podocnemis expansa, it is necessary to study their reproductive endocrinology. The purpose of this research was to evaluate and characterize plasma concentrations in gonadotrophic, gonadic, corticosterone and prolactin hormones from Giant Amazon Turtles under captive conditions. Blood samples were collected over a 15 month period. The samples were assayed by the use of radioimmunoassay, prolactin, corticosterone, LH, FSH, testosterone, 17β-estradiol and progesterone. We verified significant seasonal pattern increase in 17β-estradiol levels and decrease in progesterone levels in the course of a year, which indicates vitellogenesis. This is related to normal ovarian cycles and possibly to the functional integrity of the hypothalamus-pituitary-gonad axis of captive females. There were negative correlations between testosterone and corticosterone in the male samples, suggestive of stress (management stress) on the reproductive system. The plasma concentrations of gonadotrophic, gonadic, prolactin and corticosterone hormones may be used as a reference for further research and possible therapeutic approaches. The data collected during this research are unprecedented for this species and may serve as a reference for future research regarding the reproductive cycle of this turtle, also allowing reproductive management while in captivity. Information about these hormones must be gathered from wild populations during different periods of the year for better clarification of the reproductive physiology of this species.

Resumo Com o objetivo de obter reprodução em cativeiro de Podocnemis expansa, é necessário reunir o conhecimento a respeito de sua endocrinologia reprodutiva. O objetivo deste trabalho foi avaliar e caracterizar as concentrações plasmáticas de hormônios gonadotróficos, gonadais, corticosterona e prolactina em Tartarugas da Amazônia em condições de cativeiro. Amostras de sangue foram coletadas durante 15 meses. As amostras foram ensaiadas pelo uso de um radioimunoensáio, prolactina, corticosterona, LH, FSH, testosterona, 17β-estradiol e progesterona. Verificou-se aumento de padrão sazonal significativo nos níveis de 17β-estradiol e diminuição dos níveis de progesterona ao longo do ano, o que indica o recrutamento folicular. Isto está relacionado com ciclos ovarianos normais e possivelmente para a integridade funcional do eixo hipotálamo-hipófise-gônadas de fêmeas em cativeiro. Houve correlação negativa entre testosterona e corticosterona nas amostras do sexo masculino, sugestivos de efeito do estresse de manejo sobre o sistema reprodutivo. As concentrações plasmáticas de hormônios gonadotrofinas, gonadais, prolactina e hormônios corticosterona pode ser usado como referência para futuras pesquisas e possíveis abordagens terapêuticas. Os dados médios coletados durante a pesquisa são inéditos para a espécie e pode servir como referência para futuras pesquisas sobre o sistema reprodutivo da tartaruga, também permitindo manejo reprodutivo em cativeiro. Informações sobre esses hormônios devem ser recolhidas a partir de natureza selvagem em diferentes períodos do ano para melhor esclarecimento da fisiologia da reprodução desta espécie.

Avaliação de parâmetros bioquímicos séricos em Tartarugas-da-Amazônia (Podocnemis expansa) mantidas em cativeiro / Evaluation of serum biochemical parameters in Amazon turtles (Podocnemis expansa) hatchlings kept in captivity

Amostras de sangue de Tartaruga-da-Amazônia mantidas em cativeiro foram analisadas com o propósito de avaliar os constituintes bioquímicos séricos e de relacionar ao que já foi relatado por outros pesquisadores, além de gerar mais informações, tendo em vista a escassez de dados envolvendo a espécie estudada. Foram utilizados 35 animais, com idade entre 3 e 7 meses, os quais foram contidos fisicamente para coleta de sangue em tubo sem anticoagulante. As análises bioquímicas foram processadas através de métodos cinéticos (enzimas) e colorimétricos (demais análises), e os valores médios obtidos foram: cálcio 7,0±1,9mg/dL, fóforo 2,8±1,2mg/dL, ácido úrico 1,8±0,8mg/dL, uréia 10,4±3,9mg/dL, alanina aminotransferase (AST) 75,5±33,6 UI/L, proteína total 1,9±0,8g/dL, triglicerídeos 22,9±9,8mg/dL e colesterol 45,3±19,7mg/dL. Observou-se que os valores dos componentes séricos avaliados assemelham-se aos que foram encontrados por outros pesquisadores em estudos bioquímicos séricos com Podocnemis expansa e outras tartarugas de água doce. Importante ressaltar que, no decorrer deste estudo observou-se a escassez de dados publicados sobre parâmetros sanguíneos de tartarugas do gênero Podocnemis, especialmente a espécie Podocnemis expansa, o que corroborou a alta relevância do desenvolvimento de mais pesquisas que envolvam a questão.(AU)

Blood samples from the giant river turtle kept in captivity were analyzed in order to evaluate the serum biochemical constituents and relate to what has been reported by other researchers, beyond the purpose of generating further information, given the paucity of data involving this species. The turtle eggs were from the state of Tocantins and were obtained from direct sampling in their natural habitat. After being collected the eggs were kept in incubators and then the puppies were kept in tanks. Samples were collected after chemical restraint of these animals by intracardiac puncture or cardiocentesis. The samples were centrifuged to obtain serum. Biochemical analyzes were processed by kinetic and colorimetric methods, as described by the manufacturer, and the values obtained were: calcium 7.0±1.9mg/dL, phosphorus 2.8±1.2mg/dL, uric acid 1.8±0.8mg/dL, BUN 10.4±3.9mg/dL, alanine aminotransferase (AST) 75.5±33.6 IU/L, total protein 1.9±0.8g/dL, triglycerides 22.9±9.8mg/dL and cholesterol 45.3±19.7mg/dL. It was observed that the values of the evaluated blood components are similar to those found by other researchers in serum biochemical studies with samples of Podocnemis expansa. During this study we observed the paucity of published data on blood parameters of Podocnemis genus, especially P. expansa species, which confirmed the high relevance of the development of further research involving this topic.(AU)

Impact of jaguar Panthera onca(Carnívora: Felidae) predation on marine turtle populations in Tortuguero, Caribbean coast of Costa Rica / Efecto de la depredación por jaguares, Panthera onca (Carnívora: Felidae), sobre las poblaciones de tortugas marinas de Tortuguero, costa caribeña de Costa Rica

Little is known about the effects of jaguars on the population of marine turtles nesting in Tortuguero National Park, Costa Rica. This study assessed jaguar predation impact on three species of marine turtles (Chelonia mydas, Dermochelys coriáceaand Eretmochelys imbricata)that nest in Tortuguero beach. Jaguar predation data was obtained by using two methodologies, literature review (historical records prior the year 2005) and weekly surveys along the 29 km stretch of beach during the period 2005-2013. Our results indicated that jaguar predation has increased from one marine turtle in 1981 to 198 in 2013. Jaguars consumed annually an average of 120 (SD= 45) and 2 (SD= 3) green turtles and leatherbacks in Tortuguero beach, respectively. Based on our results we concluded that jaguars do not represent a threat to the population of green turtles that nest in Tortuguero beach, and it is not the main cause for population decline for leatherbacks and hawksbills. Future research should focus on continuing to monitor this predator-prey relationship as well as the factors that influence it so the proper management decisions can be taken.

Existe poco conocimiento sobre el impacto que tienen los jaguares sobre las tortugas marinas que anidan en el Parque Nacional Tortuguero, Costa Rica. Este estudio evaluó el impacto de la depredación de jaguar sobre tres especies de tortugas marinas (Chelonia mydas, Dermo-chelys coriáceay Eretmochelys imbricata)que anidan en Tortuguero. Los reportes de depredación fueron obtenidos empleando dos metodologías, revisión literaria (eventos registrados antes del 2005) y monitoreos semanales a lo largo de la playa (durante el periodo 2005-2013). La depredación del jaguar se ha incrementado de una tortuga en 1981 a 198 tortugas en 2013. Asimismo, los jaguares consumieron anualmente un promedio de 120 (SD= 45) y 2 (SD= 3) tortugas verdes y tortugas baula en Tortugue-ro, respectivamente. Nuestros resultados indican que los jaguares no representan una amenaza para la población de tortugas verdes que anida en Tortuguero, y no son la causa principal de la disminución poblacional de la tortuga baula y carey. No obstante, se recomienda continuar con el monitoreo con el fin de entender cómo esta interacción depredador-presa evolucionará en el futuro.

Morphological and physiological responses of seagrasses (Alismatales) to grazers (Testudines: Cheloniidae) and the role of these responses as grazing patch abandonment cues / Respuestas morfológicas y fisiológicas de los pastos marinos (Alismatales) a los herbívoros (Testudines: Cheloniidae) y el papel de estas respuestas como señales de abandono de parches de pastoreo

Green sea turtles, Chelonia mydas, are grazers influencing the distribution of seagrass within shallow coastal ecosystems, yet the drivers behind C. mydas patch use within seagrass beds are largely unknown. Current theories center on food quality (nutrient content) as the plant responds to grazing disturbances; however, no study has monitored these parameters in a natural setting without grazer manipulation. To determine the morphological and physiological responses potentially influencing seagrass recovery from grazing disturbances, seagrasses were monitored for one year under three different grazing scenarios (turtle grazed, fish grazed and ungrazed) in a tropical ecosystem in Akumal Bay, Quintana Roo, Mexico. Significantly less soluble carbohydrates and increased nitrogen and phosphorus content in Thalassia testudinum were indicative of the stresses placed on seagrasses during herbivory. To determine if these physiological responses were the drivers of the heterogeneous grazing behavior by C. mydas recorded in Akumal Bay, patches were mapped and monitored over a six-month interval. The abandoned patches had the lowest standing crop rather than leaf nutrient or rhizome soluble carbohydrate content. This suggests a modified Giving Up Density (GUD) behavior: the critical threshold where cost of continued grazing does not provide minimum nutrients, therefore, new patches must be utilized, explains resource abandonment and mechanism behind C. mydas grazing. This study is the first to apply GUD theory, often applied in terrestrial literature, to explain marine herbivore grazing behavior.

Las tortugas verdes, Chelonia mydas, son herbívoros que influencian la distribución de pastos marinos en sistemas costeros someros, sin embargo los factores que hay detrás del uso de un parche de pastos marinos por C. mydas son desconocidos. Teorías actuales se centran en calidad de alimento (contenido de nutrientes en tejido) conforme la planta responde a la alteración causada por el pastoreo; sin embargo no hay estudios que hayan monitoreado estos parámetros en un diseño natural sin manipulación del herbívoro. Para deter minar las respuestas morfológicas y fisiológicas (productividad, morfología y almacenamiento de nutrientes) que potencialmente influencian la recuperación de los pastos de la alteración por pastoreo, los pastos fueron monitoreados por un año en tres escenarios diferentes de pastoreo (pastoreo por tortuga, pastoreo por peces, sin pastoreo) en el sistema tropical Bahía de Akumal, Quintana Roo, México. Significativamente menos carbohidratos solubles y mayor contenido de nitrógeno y fósforo fueron indicativos del estrés causado por el pastoreo en los pastos. Para determinar si estas respuestas fisiológicas de los pastos son las causantes del heterogéneo comportamiento de pastoreo de C. midas, reportado en Akumal, se mapearon y monitorearon parches de pastos en intervalos de seis meses. Los parches abandonados tuvieron menor biomasa, en vez de bajo contenido de nutrientes en hoja, o de carbohidratos en raíces. Estos resultados sugieren un comportamiento modificado de renunciamiento por densidad: el umbral crítico donde el costo de pastoreo continuo no provee los nutrimentos mínimos, por lo tanto nuevos parches deberán ser utilizados, explicando así el abandono del recurso y mecanismo detrás del comportamiento de pastoreo por C. mydas. Este es el primer estudio en aplicar la teoría de renuncia por densidad, frecuentemente utilizada en la literatura terrestre, para explicar el comportamiento de pastoreo de herbívoros.

Underwater turning movement during foraging in Hydromedusa maximiliani (Testudines, Chelidae) from southeastern Brazil / Movimento de giro subaquático durante o forrageio em Hydromedusa maximiliani (Testudines, Chelidae) do Sudeste do Brasil

A type of locomotor behavior observed in animals with rigid bodies, that can be found in many animals with exoskeletons, shells, or other forms of body armor, to change direction, is the turning behavior. Aquatic floated-turning behavior among rigid bodies animals have been studied in whirligig beetles, boxfish, and more recently in freshwater turtle, Chrysemys picta. In the laboratory we observed a different kind of turning movement that consists in an underwater turning movement during foraging, wherein the animal pivoted its body, using one of the hindlimbs as the fixed-point support in the substratum. We describe, analyze and quantify this movement during foraging in Hydromedusa maximiliani, using observations made in the laboratory. We studied 3 adult specimens (2 males, 1 female) and 2 non-sexed juveniles of H. maximiliani. They were kept individually in an aquarium filled with water and small fish. They were filmed, in dorsal view, at 30 frames per second. Sequences were analyzed frame by frame and points were marked on limbs and shell to enable analysis of variation in limb flexion and extension, as well as rotation movements. While foraging, turtles frequently turned their bodies, using one hind leg as the pivot point. This underwater turning movement, in addition to slow movements with the neck stretched, or staying nearly immobile and scanning the surroundings with lateral movements of the neck (in arcs up to 180°), and fast attacks of neck, may increase prey capture rates.

Um tipo de comportamento locomotor observado em animais com corpo rígido, que pode ser encontrado em muitos animais com exoesqueleto, conchas, ou outras formas de armaduras, para mudar de direção, é o girar o corpo num plano horizontal (Turning performance). O movimento de girar o corpo flutuando na água (Aquatic floated-turning performance) entre animais de corpo rígido tem sido estudado em besouros, peixe-caixa, e mais recente na tartaruga de água doce, Chrysemys picta. No laboratório nós observamos um tipo diferente de giro que consiste em um giro subaquático, não flutuando na água, durante o forrageio, onde o animal pivota seu corpo, usando uma das patas traseiras como um ponto fixo de suporte no substrato. Nós descrevemos, analisamos e quantificamos esse movimento durante o forrageio de Hydromedusa maximiliani, usando observações feitas em laboratório. Nós analisamos três adultos (2 machos, 1 fêmea) e dois juvenis não sexados. Eles foram mantidos individualmente em um aquário preenchido água e pequenos peixes. Eles foram filmados, em vista dorsal, a 30 imagens por segundo. As sequencias foram analisadas quadro a quadro, e pontos foram marcados nos membros e no casco para permitir analisar variações angulares durante a flexão e extensão, bem como movimentos de rotação. Os membros fizeram movimentos sequencias durante o movimento de giro, mantendo sempre um dos membros posteriores como ponto fixo. Esta estratégia de forrageio associada com movimentos lentos e pescoço esticado, ou permanecer praticamente imóveis apenas observando o ambiente através de movimentos laterais do pescoço, descrevendo trajetórias em um ângulo de 180°, e ataques rápidos com o pescoço, talvez aumente seu potencial na captura de presas.

Nesting ecology of Chelonia mydas Testudines: Cheloniidae on the Guanahacabibes Peninsula, Cuba

The nesting colony of green sea turtles Chelonia mydas at Guanahacabibes Peninsula Biosphere Reserve and National Park is one of the largest in the Cuban archipelago; however, little information about its nesting ecology is available. Temporal and spatial variation in nesting and reproductive success as well as morphometric characteristics of gravid females were used to ecologically characterize this colony. Nine beaches of the Southernmost coast of Guanahacabibes Peninsula were monitored for 14 years 1998-2012 to determine green turtle nesting activity, from May to September peak nesting season in this area. Beach dimensions were measured to determine nest density using the length and the area. Afterward the beaches were divided in two categories, index and secondary. Females were measured and tagged to compare new tagged females 823 with returning tagged females 140. Remigration interval was also determined. Temporal variation was identified as the annual number of nesting emergences and oviposits per female, with apparent peaks in reproductive activity on a biennial cycle in the first six years followed by periods of annual increase in nest number 2003-2008 and periods of decreasing number of nests 2010-2012. We also found intra-seasonal variation with the highest nesting activity in July, particularly in the second half of the month. The peak emergence time was 22:00-02:00hr. In terms of spatial variation, smaller beaches had the highest nest density and nesting was more frequent 6-9m from the high tide line, where hatchling production was maximized although hatchling success was high on average, above 80. Morphometric analysis of females was made and newly tagged turtles were smaller on average than remigrants. Our results are only a first attempt at characterizing Guanahacabibes populations but have great value for establishing conservation priorities within the context of national management plans, and for efficient monitoring and protection of nesting beaches.

La colonia de Tortuga verde Chelonia mydas que anida en la Península de Guanahacabibeses es una de las más grandes del archipiélago cubano pero existe poca información disponible sobre la misma. Por ello utilizamos la variación espacial y temporal de la anidación así como el éxito reproductivo y las características morfométricas de las hembras grávidas para realizar la primera caracterización ecológica de esta colonia. Se estudiaron nueve playas durante 14 años 1998-2012 desde mayo hasta septiembre pico de anidación. Estas se dividieron en dos categorías: índices y secundarias. Las hembras fueron medidas y marcadas para comparar las nuevas hembras marcadas 823 con las remigrantes 140. Se detectó una variación temporal en la anidación a tres niveles: interanual, dentro de la temporada y durante la noche. Se observa un ciclo bienal en los primeros seis años, luego un incremento anual 2003-2008 seguido por un período de decrecimiento en las anidaciones 2010-2012. Dentro de la temporada se encontró un pico en el mes de julio aunque cambia de la primera quincena a la segunda en años diferentes y la hora de emergencia preferentemente de 22:00-02:00hr. En la variación espacial, las playas pequeñas tuvieron mayor densidad de anidación, especialmente entre los 6-9m hasta la línea media de marea alta, donde se maximiza la producción de neonatos, aunque el éxito de emergencia de los neonatos se mantuvo como promedio por encima del 80 en toda la playa. Morfométricamente las hembras remigrantes resultaron mayores como promedio que las marcadas por primera vez. Estos resultados son una primera aproximación para la caracterización de la colonia de Guanahacabibes pero tienen gran valor para establecer prioridades de conservación dentro del contexto de los planes de manejo nacionales así como para garantizar un monitoreo eficiente y la protección de las playas de anidación.

Anatomia topográfica e comportamento arterial do pâncreas em cágados trachemys scripta elegans (Wied, 1838) / Anatomy surveying and behavior in pancreatic blood tortoises trachemys scripta elegans (Wied, 1838)

O cágado, Trachemys scripta elegans, conhecido popularmente como "tigre d´água americano" é uma espécie nativa das regiões aladas da Flórida e do Mississipi, nos Estados Unidos. Foram utilizados 20 (vinte) cágados (Trachemys scripta elegans), machos e fêmeas adultos, os quais foram eutanasiados, segundo a Resolução 714 de 20 de junho de 2002 do Conselho Federal de Medicina Veterinária (CFMV). Após a eutanásia foram identificados as aortas direita e esquerda para a injeção de Neoprene látex 450, corado com pigmento específico. Para a obtenção do molde de vinil foi injetado através das aortas direita e esquerda o acetato de vinila, seguido por corrosão em ácido sulfúrico. Observou-se que o pâncreas está intimamente relacionado com o fígado, ventrículo gástrico, duodeno e vesícula biliar. Sua face cranial esta na região distal do piloro, enquanto sua porção caudal ao longo da região cranial do duodeno. Anatomicamente o pâncreas é um órgão de estrutura alongada apresentando uma superfície levemente lobada. Quanto à vascularização arterial o pâncreas é irrigado em seu plano transversal por duas arteriais oriundas da artéria celíaca, e em cada antímero por duas artérias pancreaticoduodenais na região cranial, próximo ao piloro, pela artéria pancreaticoduodenal cranial e na porção caudal, ao longo do duodeno, irrigado pela artéria pancreaticoduodenal caudal.

The turtle Trachemys scripta elegans popularly known as "American tiger water" are native regions winged Florida and Mississippi, in the United States. We used twenty (20) turtles (Trachemys scripta elegans), adult males and females, which were euthanized under Resolution 714 of June 20, 2002 the Federal Council of Veterinary Medicine (CFMV). After euthanasia were identified aortas right and left to the injection of Neoprene latex 450, stained with specific pigment. To obtain the vinyl mold aorta was injected through the right and left vinyl acetate, followed by corrosion in sulfuric acid. It was observed that the pancreas is closely related to the liver, gizzard, gall bladder, and duodenum. His face cranial this distal region of the pylorus, while its caudal along the cranial region of the duodenum. Anatomically, the pancreas is an elongated body structure featuring a lightly lobed. As to the pancreas arterial vasculature is flushed in its transverse plane of two arteries arising from the celiac artery, and each antimere two pancreaticoduodenal artery in the cranial region, close to the pylorus by the pancreaticoduodenal artery flow in the caudal portion along the duodenum.

Leptina e grelina na regulação do comportamento alimentar da tartaruga Eretmochelys imbricata (Linnaeus 1766) / Leptin and ghrelin regulates the feeding behavior of the sea turtle Eretmochelys imbricata (Linnaeus, 1766)

Durante a temporada de nidação, fêmeas de tartarugas marinhas costumam reduzir ou cessar por completo a ingestão de alimentos. Este fato sugere que o armazenamento de energia e nutrientes para a reprodução ocorra durante o período que antecede a migração para os sítios reprodutivos, enquanto estes animais ainda se encontram nas áreas de alimentação. Do ponto de vista fisiológico, tartarugas em atividade reprodutiva são capazes de permanecer longos períodos em jejum. Fatores neuroendócrinos vêm sendo recentemente apontados como os mais relevantes para a manutenção da homeostase energética de todos os vertebrados; entre eles, a leptina (hormônio anorexígeno) e a grelina (peptídeo orexígeno). Com o objetivo de compreender o mecanismo de fome e saciedade nas tartarugas marinhas, investigamos os níveis séricos destes hormônios e de outros indicadores nutricionais em fêmeas de Eretmochelys imbricata desovando no litoral do Rio Grande do Norte, Brasil. Foram coletadas amostras de sangue de 41 tartarugas durante as temporadas reprodutivas de 2010/2011 e 2011/2012. Os níveis séricos de leptina diminuíram significativamente ao longo do período de nidação, de modo a explicar a busca por alimentos ao término da temporada. Ao mesmo tempo, registramos uma tendência crescente nos níveis séricos de grelina, fator este que também justifica a remigração para as áreas de alimentação no fim do período. Não foram observadas tendências lineares para alguns dos parâmetros avaliados, entre eles: hematócrito, alanina aminotransferase (ALT), aspartato aminotransferase (AST), fosfatase alcalina (FA), gama glutamil transferase (GGT), lipoproteínas de baixa densidade (LDL) e lipoproteínas de alta densidade (HDL). É possível que a maior parte dos indicadores nutricionais tenha apresentado redução gradativa devido ao estresse fisiológico decorrente da vitelogênese e de repetidas oviposições. No entanto, é valido ressaltar que o quadro de restrição calórica por tempo prolongado ...

Reproductive female sea turtles rarely have been observed foraging during the nesting season. This suggests that prior to their reproductive migration to nesting beaches, the adult females must store sufficient energy and nutrients at their foraging grounds, and must be physiologically capable of undergoing months without feeding. Leptin (an appetite-suppressing protein) and ghrelin (a hunger-stimulating peptide) affect body weight by influencing energy intake in all vertebrates. We investigated the levels of these hormones and other physiological and nutritional parameters in nesting female hawksbill sea turtles in Rio Grande do Norte State, Brazil, by collecting consecutive blood samples from 41 turtles during the 2010/2011 and 2011/2012 reproductive seasons. We found that levels of serum leptin decreased over the nesting season, which potentially relaxed appetite suppression and led females to begin foraging either during or after the post-nesting migration. Concurrently, we recorded an increasing trend in ghrelin, which stimulated appetite towards the end of the nesting season. Both findings are consistent with the prediction that post-nesting females will begin to forage, either during or just after their post-nesting migration. We observed no seasonal trend for other physiological parameters: PCV values, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), gamma glutamyl transferase (GGT) low-density lipoprotein (LDL) and high-density lipoprotein (HDL) serum levels. The observed downward trends in general serum biochemistry levels were likely due to the physiological stress of vitellogenesis and nesting in addition to limited energy resources and probable fasting

Actividad reproductiva de Chelonia mydas (Testudines: Cheloniidae) en Isla de Aves, Venezuela (2001-2008) / Reproductive activity of Chelonia mydas (Testudines: Cheloniidae) in Isla de Aves, Venezuela (2001-2008)

Reproductive activity of Chelonia mydas (Testudines: Cheloniidae) in Isla de Aves, Venezuela (2001-2008). The second major nesting-site for green turtles in the Caribbean is Isla de Aves, an island protected as a wildlife refuge since 1972, located at 650km Northeast from La Guaira, Venezuela. In this island, the nesting population monitoring started in 1972 and in a more continuous way after 1978, when a Scientific-Naval Station was established and scientific observations started. Since historical data show that female captures had severely affected population levels in this island before 1978, this study aim to describe recent reproductive activities. For this, during the nesting seasons of 2001-2002 and 2005-2008, nesting females were measured and tagged using metal flipper tags. A total of 458 nights were sampled observing 5 154 female emergences, with a maximum of 53 in a single night. Non-observed emergences were calculated fitting the temporal distribution of observed emergences to a normal curve. Total emergences estimated varied from =637.1±106.6 in 2001 to =2 853±42.5 in 2008 (ANOVA F(6.5df)=60.37, p<0.0001). Internesting interval in the same season was estimated in =10.71±1.32 days. Clutch frequency in a nesting season was calculated as =1.71±1.6 times per female and season. Estimated number of nesting females per year varied from =373±12.5 females in 2001 to =1 669±56.1 females in 2008 (ANOVA F (5.6df)=89.42, p<0.0001); with a positive and significant trend (r=0.842, p=0.036). Results show that nesting females numbers are increasing. We suggest that the protection of the nesting area for more than 30 years, has contributed with this population increase. Rev. Biol. Trp. 60 (2): 745-758. Epub 2012 June 01.

Isla de Aves, una isla a 650km de La Guaira, Venezuela, protegida como Refugio de Fauna Silvestre, constituye el segundo sitio de mayor anidación de la tortuga verde (Chelonia mydas) (Linnaeus 1758) en el Caribe. El seguimiento de la población comenzó en 1972 y de manera más continua desde 1978. Los datos históricos indican que la captura de hembras en la isla, afectó severamente la población hasta 1978, cuando fue construida una base científico-naval. Durante las temporadas de anidación entre 2001-2008 con excepción de 2003 y 2004, las hembras fueron marcadas con placas metálicas y medidas. Asimismo, se muestreó durante 458 noches, en donde se observaron 5 154 eventos, con un máximo de 53 por noche. Los posibles eventos no observados fueron calculados ajustando la distribución temporal de eventos observados a una curva normal. El total de eventos estimados varió de =637.1±106.6 en 2001 a =2 853±42.5 en 2008 (ANOVA F(6.5gl)=60.37, p<0.0001). El intervalo entre reanidaciones fue de =10.7±1.32 días. La frecuencia de anidación se calculó en =1.71±1.6 veces por hembra. El número de hembras estimadas varió entre =373±12.5 para 2001 y =1 669±56.1 para 2008 (ANOVA F(5.6gl)=89.42, p<0.0001). La tendencia es significativa (r=0.842, p=0.036). Los resultados indican que el número de hembras que anidan en Isla de Aves ha aumentado, y se sugiere que más de 30 años de protección del área de reproducción está resultando en un creciente número de hembras.

Beach erosion and nest site selection by the leatherback sea turtle Dermochelys coriacea (Testudines: Dermochelyidae) and implications for management practices at Playa Gandoca, Costa Rica

Leatherback sea turtles (Dermochelys coriacea) nest on dynamic, erosion-prone beaches. Erosive processes and resulting nest loss have long been presumed to be a hindrance to clutch survival. In order to better understand how leatherbacks cope with unstable nesting beaches, I investigated the role of beach erosion in leatherback nest site selection at Playa Gandoca, Costa Rica. I also examined the potential effect of nest relocation, a conservation strategy in place at Playa Gandoca to prevent nest loss to erosion, on the temperature of incubating clutches. I monitored changes in beach structure as a result of erosion at natural nest sites during the time the nest was laid, as well as in subsequent weeks. To investigate slope as a cue for nest site selection, I measured the slope of the beach where turtles ascended from the sea to nest, as well as the slopes at other random locations on the beach for comparison. I examined temperature differences between natural and relocated nest sites with thermocouples placed in the sand at depths typical of leatherback nests. Nests were distributed non-randomly in a clumped distribution along the length of the beach and laid at locations that were not undergoing erosion. The slope at nest sites was significantly different than at randomly chosen locations on the beach. The sand temperature at nest depths was significantly warmer at natural nest sites than at locations of relocated nests. The findings of this study suggest leatherbacks actively select nest sites that are not undergoing erosive processes, with slope potentially being used as a cue for site selection. The relocation of nests appears to be inadvertently cooling the nest environment. Due to the fact that leatherback clutches undergo temperaturedependent sex determination, the relocation of nests may be producing an unnatural male biasing of hatchlings. The results of this study suggest that the necessity of relocation practices, largely in place to protect nests from erosion, should be reevaluated to ensure the proper conservation of this critically endangered species. Rev. Biol. Trop. 58 (4): 1237-1246. Epub 2010 December 01.

Caracterización espacio-temporal del hábitat y presencia de Dermatemys mawii (Testudines: Dermatemydidae) en la cuenca del Grijalva-Usumacinta, Tabasco, México

Presence and spatio-temporal habitat characterization of Dermatemys mawii (Testudines: Dermatemydidae) in the Grijalva-Usumacinta watershed, Tabasco, Mexico. The Central American River Turtle (Dermatemys mawii) is an endangered species that has been poorly studied. There are no reports on their population status, habitat condition, and the species distribution area is still unknown. This study analyzes the seasonal and spatial variations of their habitat and the presence/absence of D. mawii in three rivers within the Pantanos de Centla Biosphere Reserve (Tabasco, Mexico). For habitat characterization, natural segmentation of rivers was used and three sites per segment were identified, 9 in each rivers (Grijalva and Usumacinta) and 6 in Tabasquillo. Additionally, the evaluation of 11 environmental variables such as water hydrological, physicochemical characteristics and riparian and hydrophytic vegetation were carried out during two different seasons (dry and rainy). The presence/absence of species was assessed with eight fike nets that were set per segment, with a capture effort of 384 hours per trap. The capture per unit effort (CPUE) was used as an indicator of relative abundance. The results indicated spatio-temporal variations in habitat characteristics and the presence of environmental gradients. The principal components analysis (PCA) applied allowed us to determine that the first three components explained 67.8% of the environmental variability. The species presence was confirmed in all rivers, however significant differences exists in their relative abundance: the highest was registered in the Tabasquillo River where the species was present in both seasons and in all segments. Of the 11 environmental variables analyzed, the gradient, shelter and depth were the most indicative of species presence. The obtained results evidenced the importance of riparian vegetation as habitat for Dermatemys. This represents the first approach towards an action plan for a species and its habitat protection within the Pantanos de Centla Biosphere Reserve. Rev. Biol. Trop. 58 (4): 1247-1260. Epub 2010 December 01.

La tortuga centroamericana (Dermatemys mawii) es una especie en peligro de extinción pobremente estudiada. En el presente trabajo se analizaron las variaciones estacionales y espaciales del hábitat y se relacionaron con la presencia/ausencia de D. mawii en tres ríos de la Reserva de la Biosfera Pantanos de Centla (Tabasco, México). Para caracterizar el hábitat se evaluaron 11 variables (hidrológicas, fisicoquímicas del agua y de la vegetación) en dos temporadas (seca y lluviosa). Para determinar la presencia/ ausencia de la especie se colocaron 8 trampas de desvío acuáticas, empleando la captura por unidad de esfuerzo (CPUE) como indicador de la abundancia relativa. Los resultados indicaron variaciones espacio-temporales. El análisis de componentes principales (ACP) permitió determinar la variabilidad ambiental. La presencia de la especie se confirmó en los tres ríos, sin embargo la mayor abundancia relativa se registró en el Río Tabasquillo. Cuatro variables tuvieron el mayor peso como variables predictoras de la presencia de la especie. Con los resultados obtenidos, es evidente la importancia que tiene el ambiente ribereño como hábitat para Dermatemys, asimismo es posible hacer el primer acercamiento a un plan de acción para la protección de la especie y su hábitat en esta reserva.

Los huevos falsos (SAGs) facilitan el comportamiento social de emergencia en las crías de la tortuga laúd Dermochelys coriacea (Testudines: Dermochelyidae)

False eggs (SAGs) facilitate social post-hatching emergence behaviour in Leatherback turtles Dermochelys coriacea (Testudines: Dermochelyidae) nests. Hatchling emergence to the beach surface from deep sand nests occurs without parental care. Social behaviour among siblings is crucial to overcome this first challenge in sea turtles life. This study, carried out at the Caribbean coast of Colombia, describes the emergence social behaviour of hatchlings from eight nests, and assess the nests translocation effects on temporal patterns of emergence. For the first time, we propose that space released by dehydration of shelled albumen globes (SAGs) at the top of the clutch, might be a reproductive advantage, while facilitating neonates to group together in a very limited space, and favouring the synchrony of emergence. The mean time of groups emergence was of 3.3 days, varying between 1 and 6 days. We found that relocation of the nests did not significantly affect the temporal pattern of emergence, which was mainly nocturnal (77.7% of natural nests and 81.7% of translocated ones). The maximum number of emergences to the surface occurred at the lowest air temperatures (22:00h-06:00h). The selective advantage of this pattern is probably related to the greater rate of predation and mortality by hyperthermia observed during the day. Rev. Biol. Trop. 58 (3): 943-954. Epub 2010 September 01.

La emergencia de las crías de tortuga laúd eclosionadas en los nidos profundos desde la arena hasta la superficie de la playa ocurre sin ayuda parental y es el primer gran desafío de supervivencia en su ciclo de vida. Este estudio, desarrollado en la costa Caribe colombiana, describe el comportamiento social de emergencia de neonatos y evalúa el efecto de la traslocación de los nidos en los patrones temporales de emergencia. Se propone por primera vez que el espacio liberado por la deshidratación de falsos huevos (SAGs) en la nidada, representa una ventaja reproductiva al facilitar el agrupamiento de los neonatos en un espacio muy limitado y favorecer la sincronía de la emergencia. El tiempo medio registrado para la emergencia en grupo fue de 3.3 días, variando entre uno y seis días. La traslocación de los nidos no afectó el patrón temporal de emergencia que fue predominantemente nocturno (77.77% en nidos naturales y 81.65% en trasladados). Los picos máximos de emergencias a la superficie coincidieron con los periodos de menor temperatura ambiental exterior (22:00h-06:00h). La ventaja selectiva de este patrón temporal y de la emergencia sincrónica está probablemente relacionada con las mayores tasas de depredación y mortalidad por hipertermia observadas durante el día.

Nesting ecology of Podocnemis expansa (Schweigger, 1812) and Podocnemis unifilis (Troschel, 1848) (Testudines, Podocnemididae) in the Javaés River, Brazil / Ecologia reprodutiva de Podocnemis expansa (Schweigger, 1812) e Podocnemis unifilis (Troschel, 1848) (Testudines, Podocnemididae) no Rio Javaés, Brasil

Nest site has influence on incubation duration and hatching success of two Neotropical turtles, the Giant Amazon River Turtle (Podocnemis expansa) and Yellow-Spotted Side-Neck Turtle (Podocnemis unifilis - "Tracajá"). The 2000 and 2001 nesting seasons have been monitored at the Javaés River in Bananal Island, Brazil. Although they nest on the same beaches, there is a separation of the nesting areas of P unifilis and P. expansa nests on the upper parts of the beach. The incubation duration for P. expansa is influenced by the nesting period, the height of the nest from the river, the clutch size, and the grain size in the site of the nest. Nests of Podocnemis expansa placed in coarse sediments have shorter incubation duration than those placed in finer sediments. The hatching success in P. expansa is influenced by grain size, incubation duration, and nesting period. The grain size is negatively correlated with hatching success, indicating that the nests situated in finer-grained sand have better chances of successful egg hatching than those in coarser-grained sand. Nests of the end of the reproductive season have lower hatching success and incubation duration than those at the start of the season. For P. unifilis, the nesting period and nest depth influence the incubation duration; moreover, the river dynamics significantly affect the hatching success. The oscillation of the river level and the moment of initial increase, the height of the nest from the river level, and the nesting period are all decisive components for hatching success. The results of this research show the importance of protecting areas with great geological diversity, wherein the features of the environment can affect the microenvironment of nests, with consequences on incubation duration and hatching success.

O local da desova influencia a duração da incubação e o sucesso de eclosão de duas tartarugas neotropicais brasileiras, a tartaruga-da-amazônia (Podocnemis expansa) e o tracajá (Podocnemis unifilis). Monitoramos as estações reprodutivas de 2000 a 2001 nas praias do Rio Javaés na Ilha do Bananal. Apesar de as duas espécies desovarem nas mesmas praias, existe uma separação entre as áreas de desova, com P. expansa desovando nas partes mais elevadas das praias. A duração da incubação de P. expansa foi influenciada pelo período da desova, pela altura do ninho em relação ao nível do rio, pelo número de ovos e pelo tamanho do sedimento. Ninhos de P. expansa localizados em sedimentos mais grossos apresentaram uma menor duração da incubação. O sucesso da eclosão de P. expansa foi influenciado pelo tamanho do sedimento, duração da incubação e período da desova. O sucesso da eclosão se correlacionou negativamente com o tamanho do sedimento indicando que ninhos situados em areias mais finas têm maiores chances de eclodirem. Ninhos do final da temporada reprodutiva têm menor sucesso de eclosão e menor duração da incubação. Para P. unifilis, a duração da incubação é influenciada pelo período da desova e a dinâmica fluvial exerce grande efeito no sucesso da eclosão. A oscilação do nível do rio Javaés e o período da desova foram decisivos para o sucesso da eclosão. Os resultados ressaltam a importância da proteção de áreas com maior diversidade geológica onde as variáveis ambientais podem afetar o microambiente dos ninhos com reflexos na duração da incubação e no sucesso da eclosão dos filhotes.

Impacto de la luz artificial sobre la anidación de la tortuga marina Dermochelys coriacea (Testudines: Dermochelyidae), en playa Cipara, Venezuela

Impact of artificial light on nesting in the leatherback turtle Dermochelys coriacea (Testudines: Dermochelyidae) at Cipara beach, Venezuela. The number of Leatherback turtle nests and their spatial distribution was compared between years with and without artificial light, and between dark and lighted beach segments, in Cipara Beach, Paria Peninsula, Venezuela. Residents were interviewed to identify their perceptions about the impact of artificial light on sea turtles. Mean volume of sand per meter of beach was larger at La Peña, Cipara and La Remate and smaller at Varadero (p<0.001), increasing from April to June and later decreasing until August (p<0.05). Mean percentage of gravel was higher at Varadero and La Peña, and lower at La Remate and Cipara. Most interviewed people said that artificial light does not affect sea turtles. Between 2000 and 2005, 1 217 leatherback landings and 1 056 nests were observed. Successful nests increased with the years (p=0.035) as well as total nest number (p=0.015). From 2000 through 2003 there were 743 landings, 661 nests and 374 clutches. During the two years with electric light (2004-2005), there were 474 landings, 395 nests and 232 clutches. Proportion of landings with nest building decreased significantly during the years with electric light (p= 0.005), but nesting success did not vary (p= 0.402). No significant difference was found between landings per beach meter in dark and lighted sectors (p=0.244), between nests built (p=0.379) and in the rate of successful nesting (p=0.516). Dark and lighted sectors did not differ in the proportion of landings with nest building (p=0.067) and success rate (p=0.833). Rev. Biol. Trop. 57 (3): 515-528. Epub 2009 September 30.

En Playa Cipara, Península de Paria, Venezuela, se evaluó el impacto de la luz artificial sobre la anidación de la tortuga cardón. Se estimó el número de anidaciones y su distribución espacial a lo largo de la playa entre los años sin y con iluminación artificial y entre segmentos de playa iluminada y oscura. Se hicieron entrevistas a los residentes para conocer su percepción sobre el impacto de la luz artificial hacia las tortugas marinas. Entre el 2000 y 2005 se registraron 1 217 salidas de tortuga cardón; con 1 056 nidos. El número de nidos con huevos dependió significativamente del año (p=0.035) al igual que el número de nidos totales (p=0.015). En los años previos a la electricidad (2000-2003) se observaron 743 salidas, de las cuales 661 con nido y 374 nidadas confirmadas. En los dos años (2004-2005) con iluminación artificial, se contaron 474 salidas con 395 nidos y 232 nidadas. La proporción de salidas con construcción de nido disminuyó significativamente (p=0.005) en los años con luz eléctrica, pero no varió el éxito de desove (p=0.402). No se encontró diferencia significativa entre el número de salidas por metro de playa en los sectores oscuros y los iluminados (p=0.244), ni entre el número de nidos construidos (p=0.379), ni entre las anidaciones con desove (p=0.516). Tampoco en la proporción de las salidas totales que constituyeron anidaciones (p=0.067) entre los sectores iluminados y oscuros, ni en la proporción de nidos exitosos (p=0.833). El volumen medio de arena por metro de playa fue mayor en La Peña, Cipara y La Remate y menor en Varadero (p<0.001), aumentando de abril a junio y posteriormente disminuyó un poco hasta agosto (p<0.05). El porcentaje medio de gravas fue mayor en Varadero y La Peña y menor en La Remate y Cipara. La mayoría de los entrevistados consideraron que la luz artificial no afecta a las tortugas marinas.

The use of rocuronium in giant Amazon turtle Podocnemis expansa (Schweigger, 1812) (Testudines, Podocnemididae) / Uso do rocurônio em tartaruga da Amazônia Podocnemis expansa (Schweigger, 1812) (Testudines, Podocnemididae)

PURPOSE: To determine whether rocuronium would provide safe, short-term immobilization in Podocnemis expansa. METHODS: Twenty P. expansa, weighing on average 1.59 ± 0.28 kg, were subjected to two protocols: G1 0.25 mg/kg IM of rocuronium and 0.07 mg/kg IM of neostigmine, while G2 received 0.50 mg/kg IM of rocuronium and 0.07 mg/kg IM of neostigmine. The drugs were applied, respectively, in the left and right thoracic members. Assessments were made of the anesthetic parameters of respiratory frequency, heartbeat, righting reflex, cloacal relaxation, palpebral and pupilar reflexes, easy handling, muscle relaxation, locomotion, response to pain stimuli in the right thoracic members, pelvic members and tail, ambient humidity and temperature. RESULTS: They were not found statistical differences between the dosages for the majority of the assessments. G1 was as efficient as G2. A consistent neuromuscular blockade effect was recorded 12 ± 4.21 minutes in G1 and G2. All the animals were recovered in 150 minutes. CONCLUSIONS: Administration of rocuronium at dose of 0.25 to 0.5 mg/kg IM is a safe and effective adjunct to clinical proceedings or pre-anesthetics in P. expansa. Because rocuronium does not provide any analgesic or sedative effects, the duration of neuromuscular blockade without anesthesia should be minimized to avoid undue stress.

OBJETIVO: Determinar se o rocurônio promove imobilização segura e de curta duração em Podocnemis expansa. MÉTODOS: Vinte P. expansa com média de peso 1,59 ± 0,28 kg, foram submetidas a dois protocolos: G1 recebeu rocurônio 0,25 mg/kg IM e neostigmina 0,07 mg/kg IM enquanto G2 rocurônio 0,50 mg/kg IM e neostigmina 0,07 mg/kg IM, aplicados no membro torácico esquerdo e direito, respectivamente. Observaram-se os parâmetros anestésicos: freqüência respiratória e cardíaca, reflexo de endireitamento, relaxamento do esfíncter da cloaca, reflexo palpebral e pupilar, facilidade de manipulação, relaxamento muscular, locomoção, resposta aos estímulos dolorosos no membro torácico direito, nos membros pelvinos e na cauda, temperatura e umidade ambiental. RESULTADOS: Não foram encontradas diferenças estatísticas entre as doses para a maioria dos parâmetros e o G1 foi tão eficiente quanto o G2. Um bloqueio neuromuscular consistente foi observado aos 12 ± 4,21 minutos tanto no G1 como no G2. A recuperação de todos os animais ocorreu em até 150 minutos. CONCLUSÕES: Administração de rocurônio nas doses 0,25 e 0,50 mg/kg IM é segura e efetiva para os procedimentos clínicos ou pré-anestésicos em P. expansa. Como o rocurônio não produz efeitos sedativos ou analgésicos, a duração do bloqueio neuromuscular sem anestesia deverá ser minimizado para evitar estresse.

Enzymes of energy metabolism in hatchlings of amazonian freshwater turtles (Testudines, Podocnemididae) / Enzimas do metabolismo energético em quelônios amazônicos (Testudines, Podocnemididae) recém-eclodidos

The metabolic profiles of selected tissues were analyzed in hatchlings of the Amazonian freshwater turtles Podocnemis expansa, P. unifilis and P. sextuberculata. Metabolic design in these species was judged based on the key enzymes of energy metabolism, with special emphasis on carbohydrate, lipid, amino acid and ketone body metabolism. All species showed a high glycolytic potential in all sampled tissues. Based on low levels of hexokinase, glycogen may be an important fuel for these species. The high lactate dehydrogenase activity in the liver may play a significant role in carbohydrate catabolism, possibly during diving. Oxidative metabolism in P. sextuberculata appears to be designed for the use of lipids, amino acids and ketone bodies. The maximal activities of 3-hydroxyacyl-CoA dehydrogenase, malate dehydrogenase, glutamine dehydrogenase, alanine aminotransferase and succinyl-CoA keto transferase display high aerobic potential, especially in muscle and liver tissues of this species. Although amino acids and ketone bodies may be important fuels for oxidative metabolism, carbohydrates and lipids are the major fuels used by P. expansa and P. unifilis. Our results are consistent with the food habits and lifestyle of Amazonian freshwater turtles. The metabolic design, based on enzyme activities, suggests that hatchlings of P. unifilis and P. expansa are predominately herbivorous, whereas P. sextuberculata rely on a mixed diet of animal matter and vegetation.

O perfil metabólico de vários tecidos foi analisado em quelônios aquáticos recém-eclodidos: Podocnemis expansa, P. unifilis e P. sextuberculata. O potencial metabólico dessas espécies foi avaliado por meio das atividades absolutas das enzimas do metabolismo energético com ênfase no metabolismo dos carboidratos, lipídios, aminoácidos e corpos cetônicos. Todas as espécies estudadas apresentaram alto potencial glicolítico em todos os tecidos analisados. Com base nos baixos níveis da enzima hexoquinase, as reservas de glicogênio podem ser importantes substratos energéticos para estas espécies. A alta atividade da lactato desidrogenase no fígado pode indicar que este órgão desempenha um importante papel no metabolismo dos carboidratos, possivelmente relacionado com a resistência ao mergulho prolongado. O perfil metabólico de P. sextuberculata parece organizado para utilizar preferencialmente lipídios, aminoácidos e corpos cetônicos. Os dados das atividades máximas das enzimas 3-hidroxi-acil-Co A desidrogenase, malato desidrogenase e succinil-Co A ceto-transferase, especialmente no músculo branco e no fígado dessa espécie corroboram esta hipótese. Por outro lado, os carboidratos e os lipídios parecem ser os principais substratos metabólicos de P. expansa e P. unifilis, muito embora, os corpos cetônicos e aminoácidos sejam importantes metabólitos para sustentar o potencial oxidativo nessas espécies. Os dados enzimáticos parecem estar correlacionados com o hábito alimentar e o estilo de vida dos quelônios de água doce da Amazônia. O perfil metabólico sugere que os recém-eclodidos de P. unifilis e P. expansa são predominantemente herbívoros, enquanto que P. sextuberculata pode depender de uma dieta mista de material vegetal e proteína animal.

Population ecology of a freshwater turtle Kachuga tentoria near Panchnada (Etawah: U.P.) and its role as water purifier.

The present study deals with biology, ecology and population dynamics of freshwater turtle Kachuga tentoria and its role as water purifier. The study area Panchnada is the site, where five important national rivers meet together and is preserving an appreciable population of nine species of fresh water turtles. Kachuga tentoria was located at all the sampling stations surveyed by the authors, and hence selected for the present study. Different activities (nesting, incubation, predation and other reproductive aspects), climatic conditions, habitat, population density and morphometric features were worked out in detail. A time bound conservation strategy is needed to save this species from extinction. In situ conservation will be more helpful for the recruitment of the population of this species. It will help in the "hatch and release programme" to clean different polluted national rivers.

Beach dynamics and nest distribution of the leatherback turtle (Dermochelys coriacea) at Grande Riviere Beach, Trinidad & Tobago

Grande Riviere Beach in Trinidad and Tobago is an important nesting site in the Caribbean for the Critically Endangered leatherback sea turtle, Dermochelys coriacea. Community members were concerned that beach erosion and seasonal river flooding were destroying many of the nests deposited annually and thought that a hatchery was a possible solution. Over the 2001 turtle nesting season, the Institute of Marine Affairs (IMA) assessed the spatial and temporal distribution of nests using the Global Positioning System recorded to reference points, and beach dynamics using permanent bench mark profile stations, to determine areas of high risk and more stable areas for nesting. A total of 1449 leatherback nests were positioned. It was evident that at the start of the season in March, the majority of leatherback nests were deposited at the eastern section of the beach. After May, there was a continuing westward shift in nest distribution as the season progressed until August and beach erosion in the eastern section became predominant. The backshore remained relatively stable along the entire beach throughout the nesting season, and erosion was predominant in the foreshore at the eastern section of the beach, from the middle to the end of the season. Similar trends in accretion and erosion were observed in 2000. River flooding did not occur during the study period or in the previous year. With both high risk and more stable regions for turtle nesting available at Grande Riviere Beach, there was no compelling evidence to justify the need for a hatchery

Interrenal responses to high ambient temperature in soft-shelled turtle, Lissemys punctata punctata.

An exposure to ambient temperature of 25 degrees C had no perceptible effect on interrenal function but further increase of temperature to 35 degrees C caused nuclear hypertrophy with increase of nuclear diameter, RNA concentration, acid phosphatase and alkaline phosphatase activities, accompanied by quantitative depletions of cholesterol (free, esterified and total) and ascorbic acid levels in the interrenal gland of the soft-shelled turtle Lissemys p. punctata. Similar manifestations of stimulation, except in the nucleus, were marked after exposure to 38 degrees C, but the degree of response in respect of esterified and free cholesterol levels was higher at 38 degrees C than at 35 degrees C. Moreover, withdrawal of 38 degrees C temperature and subsequently maintaining at 25 degrees C for 15 days showed reverse manifestations to those of 35 degrees C/38 degrees C, leading to a tendency towards normalcy. It is suggested that high a ambient temperature of 35 degrees C significantly stimulates interrenal function of Lissemys turtles, but further increase of 38 degrees C does not cause further overall stimulation, and withdrawal of higher temperature (38 degrees C) shows a tendency towards normalcy. It is also suggested that (a) high ambient temperature causes thermal stress, (b) it is reversible and (c) it acts on interrenal activity presumably via CRF-ACTH-axis in turtles.

Oxygenation properties of hemoglobin from the turtle Geochelone carbonaria

The oxygen-binding properties of hemoglobin (Hb) from the adult terrestrial turtle Geochelone carbonaria are described. Turtle hemoglobins have a low intrinsic oxygen affinity and a low sensitivity to an endogenous cofactor (ATP) usually present at high concentrations in the reptile erythrocytes. The amplitude of the Bohr effect for O2 binding was virtually the same in the absence and presence of saturating ATP concentrations (deltalogP50/deltapH, about -0.60) and increased in the total hemolysate (-0.83). The large Bohr effect found in G. carbonaria Hb may be important for 02 delivery to the tissue. The degree of cooperativity displayed by Hb for 02 binding ranged between 1.5 and 2.0 in stripped solution and total hemolysate. These observations suggest the stability of the low affinity conformation, which needs to be confirmed by additional experiments.