Neonatal biometry and characterization of Amazonian Turtle nests (Podocnemis expansa)

The present study aimed to study the reproduction of the Amazon turtle (Podocnemis expansa) through the evaluation of the reproductive parameters of adult females. This study was carried out in the Crixás-Açu River, municipality of Mundo Novo, state of Goiás, Brazil. In September, the biometrics of 20 females were evaluated during the spawning period. Their nests were marked for subsequent evaluation of hatchlings, measuring the distances of each nest to the river and vegetation. The second stage consisted of the evaluation of hatchlings and characterization of nests after egg hatching. The datawere tested using the Pearson Correlation to measure the degree of linear correlation between the variables analyzed, such as the parameters of females, hatchlings, nests, and eggs. Nest depth was positively correlated with the number of eggshells found. We also found a correlation between the number of eggsshells and the distance of nests to the vegetation. Although moderate, this result indicates that as the distance to the vegetation increases, the number of eggshells found in nests decreases. The spawning site for Amazon turtle breeding is crucial to determine a higher number of eggshatching and better development of hatchlings. However, the literature is still very scarce regarding the choice of spawning grounds and the influence that vegetation may have on the development of freshwater turtle hatchlingsin Brazil.

Influencia de la vigilancia en una zona rocosa dentro de un área marina protegida, Pacífico Central de Costa Rica / Surveillance influence in a rocky shore within a marine protected area, Central Pacific of Costa Rica

Resumen Los intermareales rocosos son sitios importantes para peces, aves, invertebrados y algas entre otros, que se utilizan para la extracción de recursos alimenticios para las comunidades costeras. Se presentan los resultados de la evaluación de una costa rocosa en el Pacífico Central de Costa Rica (Refugio Nacional de Vida Silvestre Playa Hermosa-Punta Mala), usando indicadores biológicos propuestos por el protocolo del Ministerio de Ambiente y Energía. Se analizó la influencia de la vigilancia en dos sitios dentro de un AMP sobre el intermareal rocoso. La recolección de datos se realizó durante la época seca y la época lluviosa de 2015. Los datos mostraron que Nerita scabricosta presentó muchas colonias formadas por pocos individuos. La cobertura de macroalgas y los invertebrados bajo las rocas mostraron una leve diferencia entre los niveles de vigilancia. La densidad de Tetraclita stalactifera no mostró variaciones. Se sugiere la hipótesis que el daño mecánico asociado al turismo, pesca y extracción, está influyendo sobre los organismos de la zona rocosa. Algunos de los bioindicadores utilizados mostraron ser influenciados por los niveles de vigilancia y aplicación de las medidas de manejo.

Abstract Rocky intertidal are important sites for fish, birds, invertebrates and algae, among others, which are used for the extraction of food resources for coastal communities. We present the results of conservation assessment of a rocky shore in the Central Pacific of Costa Rica (Playa Hermosa-Punta Mala National Wildlife Refuge) using the biological indicators proposed by the National Environmental Ministry. This study aims to analyze the influence of surveillance, between two sites, over the rocky shore habitat. The sampling was carried out during both the dry and rainy seasons in 2015. Our data shows that Nerita scabricosta -harvested in small-scale fisheries- presents a high number of colonies formed by few individuals. Moreover, the abundance varied between seasons, probably due to a storm surge. Macroalgae differed slightly among sites, where turf had higher percentage coverage in low surveillance areas, while brown algae had higher coverage in high surveillance areas. Mechanical damage (abrasion due to rocks overturning) associated with tourism and harvesting could be influencing the low surveillance area, explaining these differences. Macroalgae presented a seasonal change, probably related to the storm surge. The density of the Tetraclita stalactifera did not exhibit variations. The surveillance level and enforcement influenced some bioindicators of the rocky shore, and therefore could be used to assess the extractive pressure. Rev. Biol. Trop. 66(3): 984-995. Epub 2018 September 01.

Conservación y actividad reproductiva de tortuga lora ( Lepidochelys olivacea ) en la playa de anidación solitaria Punta Banco, Pacifico Sur de Costa Rica. Recomendaciones de manejo a través de dieciséis años de monitoreo / Conservation and reproductive activity of Olive Ridley sea turtles (Lepidochelys olivacea) in Punta Banco, a solitary nesting beach in South Pacific Costa Rica: Management recommendations after sixteen years of monitoring

Resumen Se realizó un monitoreo de la actividad de anidación de tortugas marinas en Punta Banco, Pacífico Sur de Costa Rica, de forma ininterrumpida por diez y seis años, acompañado por actividades de conservación como la relocalización de los nidos en viveros. Se realizaron análisis de éxito de eclosión para nidos "in situ" y en vivero. Evaluamos por este medio la biología reproductiva de la tortuga lora (Lepidochelys olivacea), por mucho la tortuga más común que anida en Punta Banco (98% de las tortugas observadas). Entre 1996 y 2011, se llevó a cabo el monitoreo diario de las actividades de anidación de julio a diciembre. Marcamos un total de 1 239 tortugas L. olivacea y registramos 4 130 eventos de anidación. El total de anidaciones para L. olivacea varió de 239 en el año 1996 a 402 en 1999, mientras que el número de hembras avistadas varió de 18 en 1996 a 146 en 1999. Las hembras presentaron un largo curvo del caparazón promedio de 66.8cm y ancho curvo de caparazón promedio de 70.7cm. La media para el tamaño de las nidadas fue de 96.7 huevos, con una frecuencia de puesta observada de 1.07 nidos/hembra y un intervalo de puesta observado de 19.95 días. El éxito de eclosión de nidos "in situ" fue de 61.38%, mientras que el éxito de nidos relocalizados en viveros fue de 77.9%. La población de L. olivacea en Punta Banca muestra una tendencia positiva.

Abstract Sea turtle nesting activity was monitored in Punta Banco, South Pacific Costa Rica uninterruptedly for sixteen years, accompanied by conservation activities such as nest relocation in hatcheries. Hatching success evaluations were held for "in situ" and relocated nests. We hereby evaluate the reproductive biology of the olive ridley sea turtle (Lepidochelys olivacea), by far the most common turtle sea turtle nesting in Punta Banco (98% of observed turtles). Daily monitoring of nesting activities was held every year from July to December, from 1996 to 2011. We tagged a total of 1 239 turtles and recorded 4 130 nesting events. The number of recorded nesting events per nesting season ranged from 239 in 1996 to 402 in 1999, whereas the number of observed females ranged from 18 in 1996 to 146 in 1999. Nesting females had an average curved carapace length of 66.8cm and an average curve carapace width of 70.7cm. The average clutch size was 96.7, with an observed frequency of 1.07 nests/female and an nesting interval of 19.95 days. Hatching success of "in situ" nests was 61.38%, whereas hatching success for nests relocated into hatcheries was 77.9%. The L. olivacea population in Punta Banco beach displays a a positive trend. Rev. Biol. Trop. 63 (Suppl. 1): 383-394. Epub 2015 April 01.

Selección de sitios de anidación de Lepidochelys olivacea (Testudines: Cheloniidae) en el Pacífico Sur de Costa Rica / Nest-site selection of Lepidochelys olivacea (Testudines: Cheloniidae) in the South Pacific region of Costa Rica

Resumen La selección del sitio de anidación en tortugas marinas es determinante para la sobrevivencia de la progenie, sin embargo para Lepidochelys olivacea existe poca información al respecto. Este trabajo se enfocó en determinar si L. olivacea selecciona sus sitios de anidación de acuerdo a un patrón o preferencia espacial determinada, o si por el contrario distribuye sus nidos aleatoriamente en la playa. La recolección de datos se realizó entre julio y setiembre del 2011, en las playas de Piro y Pejeperro, Península de Osa, Costa Rica. La ubicación del nido se evaluó midiendo las distancias entre la línea de marea y el nido, entre el nido y la vegetación, y determinando la posición del nido con respecto a los sectores marcados cada 100m en la playa. En ambas playas, las tortugas mostraron una marcada preferencia por anidar lo más lejos posible de la línea de marea, lo cual protege a sus nidos de inundación pero los expone a un mayor riesgo de depredación. Además, en playa Piro se detectó una mayor concentración de nidos cerca de la desembocadura del río, y en las cercanías de un estero en el caso de Pejeperro. Si estas zonas están asociadas a un mayor éxito de eclosión, es posible que las tortugas estén regresando y seleccionado esos sitios por impronta o filopatría. Futuras investigaciones deberán enfocarse en determinar si en eventos de anidación sucesivos, L. olivacea muestra repetibilidad y mantiene sus preferencias de anidación a nivel de individuo.

Abstract In sea turtles, nest-site selection plays a key role in the survival of the offspring, with a direct influence on the sex of the hatchlings, incubation period, embryonic mortality, and hatchling size. Nest-site choice has been studied for most sea turtle species, but the information for Lepidochelys olivacea, the most abundant sea turtle species, is scarce. The present work explores the spatial nesting patterns of L. olivacea and seeks to determine whether this species employs a scatter nesting strategy or chooses to clump its nests based on a specific spatial preference. Night patrols were conducted between July and September 2011 at the beaches of Piro and Pejeperro, located in the Osa Peninsula, in the South Pacific region of Costa Rica. Nest-site location was evaluated by measuring the distance from the tide line to the nest, distance from nest to vegetation, and by noting beach sector according to beach-marker setup. In total, 84 nesting turtles were observed. Sea turtles in both beaches showed a strong preference to locate their nests as far from the tide line as possible, crawling longer distances when presented with wider stretches of beach. Turtles nesting at Piro beach also favored areas that were close to the river mouth, while turtles at Pejeperro preferred to nest near an estuary. It seems that the main driving force that influences L. olivacea to choose a nest site is to protect the eggs from tidal inundation, even if this means a higher predation risk from nesting too close to the vegetation, in addition to a longer trip to the ocean for both the female adult and the hatchlings. Nests near rivers and estuaries may have higher hatching success, which could prompt females to return and select these areas due to imprinting or philopatry. Future research focused on recapture could provide valuable information on individual behavior, and prove whether or not L. olivacea shows strong nest-site fidelity and repeatability of nesting preferences at the individual level. Rev. Biol. Trop. 63 (Suppl. 1): 375-381. Epub 2015 April 01.

Histología gonadal y criterios fenotípicos de maduración en las tortugas marinas Chelonia mydas y Eretmochelys imbricata (Testudines: Chelonidae) de Cuba

Gonadic histology and phenotypical maturation criteria in the marine turtles Chelonia mydas and Eretmochelys imbricata (Testudines: Chelonidae) from Cuba. Gonad maturity is usually evaluated through macroscopic analysis of the gonads. In sea turtles, the maturation stages are associated with body size, depending on the studied marine stock. Fishermen classify turtles bigger than 65.0cm as sexually mature. If they have secondary sex characters they are recorded as breeding males. We compared body size with macroscopic and microscopic gonad characteristics in two Cuban turtles. Eighteen individuals of C. mydas and twenty of E. imbricata was obtained from the legal fishery stock of Jardines del Rey Archipelago (Cuba), from October 2005 and 2006. In males, breeding condition (maximum spermiogenesis) was checked by histological analysis of the testes. In females, sexual maturity was identified by the presence of vitellogenic follicles or ovarian corpora. Most males were immature (C. mydas: 79.0cm; E. imbricata: 73.1±4.9cm, n=3) and lacked secondary sex characters. Some E. imbricata without a developed penis were in spermatogenic stages II to IV (i.e. pubescent). Most females were immature (C. mydas: 79.6±7.7cm, n=17; E. imbricata: 69.0±7.1cm, n=16; i.e.prepubescent and pubescent. The prepubescent females had ovaries with previtellogenic follicles near 1.0mm in a compact and yellowish stroma. The pubescent females had ovaries with previtellogenic follicles between 2.0 and 3.0mm. The stroma was more loosened and irrigated than in prepubescent turtles. The finding of spermatogenic activity in pubescent males indicates asynchrony between testicular and penial development in E. imbricata. The current phenotypical approach used by fishermen is not enough to determine sexual maturation in these turtles. The minimal size tentatively should be changed to: C. mydas: above 93.0cm and E. imbricata above 79.0cm. Rev. Biol. Trop. 58 (1): 287-298. Epub 2010 March 01.

La madurez gonadal se suele evaluar a través del análisis macroscópico de las gónadas. En las tortugas marinas, las etapas de maduración están asociadas con el tamaño del cuerpo, dependiendo de la población estudiada. Los pescadores clasifican las tortugas que miden más de 65.0cm como maduras sexualmente. Si tienen los caracteres sexuales secundarios se registran como machos en edad reproductora. Nosotros comparáramos el tamaño del cuerpo con las características gonadales macroscópicas y microscópicas de dos tortugas de Cuba. Se obtuvieron dieciocho individuos de C. mydas y veinte de E. imbricata en la pesquería legal del Archipiélago Jardines del Rey (Cuba), entre octubre de 2005 y 2006. En los machos, el estado reproductivo (máxima espermiogénesis) se comprobó mediante el análisis histológico de los testículos. En las hembras, la madurez sexual fue identificada por la presencia de folículos vitelogénicos u ovarios corpora. La mayoría de los machos eran inmaduros (C. mydas: 79.0cm; E. imbricata: 73.1±4.9cm, n=3) y carecían de los caracteres sexuales secundarios. Algunos E. imbricata que no tenían un pene desarrollado se encontraban en fases espermatogénicas entre II y IV (p. ej. pubescentes). La mayoría de las hembras eran inmaduras (C. mydas: 79.6±7.7cm, n=17; E. imbricata: 69.0±7.1cm, n=16; p. ej. prepubescente y pubescente). Las hembras prepubescentes tenían ovarios con folículos previtelogénicos de cerca de 1.0mm en un estroma compacto y amarillento. Las hembras pubescentes tenían ovarios con folículos previtelogénicos entre 2.0 y 3.0mm. El estroma fue más distendido e irrigado que en las tortugas pubescentes. El hallazgo de actividad espermatogénica en machos pubescentes indica la asincronía entre el desarrollo de testículos y pene en E. imbricata. El criterio fenotípico actual utilizado por los pescadores no es suficiente para determinar la madurez sexual de estas tortugas. La talla mínima tentativa debe cambiar a: C. mydas: por encima de 93.0cm y E. imbricata por encima de 79.0cm.

Características da reprodução de tartarugas marinhas (Testudines, Cheloniidae) no litoral sul da Bahia, Brasil / Reproduction of sea turtles (Testudines, Cheloniidae) in the Southern Coast of Bahia, Brazil

Poucos estudos foram realizados sobre a nidificação de tartarugas marinhas no litoral sul da Bahia, região que está passando por um processo rápido de ocupação turística que pode ameaçar ainda mais estas espécies. Por estes motivos, este estudo teve como objetivos identificar as espécies de tartarugas marinhas que desovam no local e descrever as principais características de suas ninhadas. Durante quatro temporadas reprodutivas, de 2004 a 2008, foram identificados e monitorados os ninhos encontrados nas praias localizadas entre Uruçuca e Itacaré no litoral sul da Bahia. As variáveis coletadas foram: tamanho de ninhada, duração da incubação, sucesso de eclosão e fases de mortalidade embrionária. Foi registrada uma média de 37 ± 6,2 ninhos por temporada, com maior freqüência de ninhos das espécies Caretta caretta e Eretmochelys imbricata, tendo sido registradas também desovas esporádicas de Chelonia mydas. A temporada de desova de C. caretta ocorre de outubro a janeiro e de E. imbricata de dezembro a março. Este deslocamento temporal das temporadas reprodutivas pode estar relacionado a uma adaptação para minimizar a competição interespecífica. Além da época de nidificação, as duas espécies diferiram no tamanho de suas ninhadas, mas não diferiram na duração da incubação e no sucesso de eclosão. Diante dos resultados, acredita-se que áreas com baixa concentração de ninhos também devem ser alvo de programas de conservação, devido à sua relevância para a ampliação da variação genotípica e, sobretudo, fenotípica, das espécies de tartarugas marinhas, de forma que as mesmas possam se adaptar e sobreviver às constantes ameaças às quais estão submetidas. Tais programas de conservação podem ser estabelecidos por meio de parcerias entre organizações não governamentais e instituições privadas e a instituição governamental responsável pela conservação das tartarugas marinhas (Centro TAMAR/ICMBio).

Few studies have been carried out on nesting of sea turtles in the southern coast of Bahia, an area that is experiencing a fast process of tourist occupation what can increase levels of threat to these species. Thus, this study aimed to identify sea turtle species that nest in the area and to describe the main characteristics of their clutches. During four reproductive seasons, from 2004 to 2008, we identified and monitored nests found at beaches located between the municipalities of Uruçuca and Itacaré, in the southern coast of Bahia. The collected variables were: clutch size, incubation duration, hatching success and stages of embryonic mortality. We registered an average of 37 ± 6.2 nests per season, with nests of Caretta caretta and Eretmochelys imbricata being more frequent, along with sporadic nests of Chelonia mydas. Nesting season of C. caretta extends from October to January and that of E. imbricata from December to March. This temporary displacement of reproductive seasons might be related to a selective adjustment to minimize competition among species. Besides the time of nesting, the two species differed also in clutch size, but they did not differ in incubation duration and in hatching success. According to our results, we believe that areas with low concentration of nests should also be a target of conservation programs, due to their relevance to the increase of genotypic, and specially fenotypic, variation of sea turtle species, so that Brazilian populations can adapt and survive to the constant threats. Those conservation programs can be established by partnerships between non-governmental organizations and private institutions and the Brazilian government institution for the conservation of sea turtles (Centro TAMAR/ICMBio).

Ecologia reprodutiva de Hydromedusa tecifera (Testudines: Chelidae) no sul do Brasil / Reproductive ecology of Hydromedusa tectifera (Testudines: Chelidae) in southern Brazil

Existem poucos dados na literatura sobre a reprodução de Hydromedusa tectifera (Chelidae), e estes se referem a indivíduos de cativeiro. A ecologia reprodutiva da espécie foi verificada através de monitoramentos não sistemáticos entre 1996 e 2002 na Estação Ecológica do Taim, no extremo sul do Brasil, com a intenção de reunir informações sobre a reprodução da espécie em ambiente natural. Foram encontrados 46 ninhos da espécie, entre intactos e predados. As ninhadas tiveram, em média, 11,6 ovos que apresentaram um tamanho médio de 36,5 x 23,9 mm. A média do peso dos ovos foi de 11,1 g e o seu volume individual resultou em uma média de 10148,31 mm³. Os ninhos alcançaram uma profundidade média de 11,1 e 5,8 cm da superfície ao primeiro ovo. A variação do volume dos ovos de um mesmo ninho foi menor (CV = 4,71 por cento) do que entre diferentes ninhos (CV = 12,32 por cento). A largura dos ovos foi positivamente dependente do seu comprimento. Já em uma mesma ninhada, o número de ovos não dependeu do seu tamanho e do seu volume. Foram observadas desovas nos meses de novembro e dezembro, mas a maioria delas ocorreu na segunda quinzena de novembro. A espécie desovou com maior freqüência no período das 18 às 20 horas, e em áreas com certa inclinação do substrato, entre 20º e 30º de declividade. A maior abundância de ninhos foi observada até 5 m de distância da lagoa. Os resultados encontrados demonstram congruência entre os dados obtidos para H. tectifera e aqueles existentes para cágados-de-pescoço-comprido da Austrália e para as espécies de Chelidae do extremo sul do Brasil.

The few available information on the reproductive behavior of Hydromedusa tectifera (Chelidae) are based on captive individuals. The H. tectifera reproductive biology was verified from 1996 to 2002 by non-systematic surveys in the Estação Ecológica do Taim, southern Brazil. Forty-six intact and damaged nests of the species were found. Mean clutch size was 11.6 eggs which exhibited a mean size of 36.5 x 23.9 mm and an average weight of 11.5 g. Individual mean eggs volume resulted an average of 10148.31 mm³. Nests had an average depth of 11.1 and 5.8 cm from the surface to the first egg. The eggs volume variation in the same nest was smaller (CV = 4.71 percent) than among different nests (CV = 12.32 percent). The eggs width was positively dependent of their length. In the same hatch the number of eggs did not depended of their size or volume. Nesting behavior was observed in November and December. The species showed higher frequency for nesting between 6 and 8 p.m., in areas with certain inclination of the substratum, between 20º and 30º of declivity. Higher nest abundance was verified up to 5 m from the lagoon. The results show that the data obtained for H. tectifera are similar to those previously reported for Australian snake-necked turtles and for species of Chelidae from southern Brazil.

Macromorfometría de juveniles de Geochelone sulcata (Testudines: Testudinidae) en Costa Rica / Gross morphometry of young Geochelone sulcata (Testudines: Testudinidae) in Costa Rica

The African Spur tortoise, Geochelone sulcata, has been introduced to Costa Rica. A total of 31 tortoises were measured for 26 gross morphometry parameters. All individuals measured were inmature, aged from 5 to 34 months, and were born in captivity in La Garita de Alajuela, Costa Rica. Mean straight carapace length was 83.1 mm, mean straight plastron length was 68.3 mm and mean maximum height was 46.2 mm. All the measurements were correlated, except tail length and cloacal distance. Weight had the highest positive allometry coefficient. All the variables were joined in two Principal Components; tail length and cloacal distance in Factor 2 and the rest of them in Factor 1. Lack of correlation among tail measures and the other variables as well as their inclusion in a different Factor could be related with an incipient development of sexual dimorphism characters

Se midieron 31 ejemplares de tortuga africana de espolones Geochelone sulcata para la realización de un estudio biométrico. Se consideraron 26 medidas morfológicas para cada individuo. Las tortugas tenían una edad de entre 5 y 34 meses, y ninguna había alcanzado la madurez sexual. Todas ellas habían nacido en cautiverio en La Garita de Alajuela, Costa Rica, donde son una especie introducida. La longitud recta del espaldar fue de 83.1 mm, la anchura recta del espaldar de 68.3 mm y la altura máxima media de 46.2 mm. Todas las medidas estaban correlacionadas entre sí, salvo la longitud de la cola y la distancia cloacal. El mayor coeficiente de alometría positiva correspondió a la variable Peso. El mayor coeficiente de alometría negativa correspondió a la anchura a nivel de los escudos gulares. Todas las variables se agruparon en dos componentes principales, la longitud de la cola y la distancia cloacal en el Factor 2 y el resto en el Factor 1. La falta de correlación de las medidas de la cola así como su inclusión en un factor aparte al resto de la muestra podría responder a un proceso incipiente de diferenciación sexual

Mortalidad embrionaria y éxito de eclosion en huevos de Trachemys scripta (Testudines: Emydidae) incubados en un área natural protegida / Embryonic mortality and hatching rate of trachemys scripta (Testudines: Emydidae) eggs artificially grown in a protected natural area

In the northeast of Costa Rica, illegal collecting, habitat destruction and heavy predation on adult females, young and eggs of Trachemys scripta produced a population decline in recent years. The slider turtle has a high reproductive potential and nests were relocated. Between January and March 1991,179 nests (3220 eggs) were collected from natural areas of Ca o Negro National Wildlife Refuge, Costa Rica and relocated for incubation under natural conditions in a protected site. The mean of number of eggs per clutch was 19.5 +/- 4.5 (range 8 to 31) and the mean incubation period was 77.4 +/- 11.4 days (range 50 to 110 days). The mean hatching success was 89.6 +/- 3.4 percento (range 60.0 to 100 percento).The mean early and mid embryonic mrtality was 5.5 +/- 4.3 percento, the average late embryonic mortality was 8.5 +/- 3.5 percento and infertility 1.8 +/-1.0 percento

Crecimiento, conversión de alimento y mortalidad de Eretmochelys imbricata (Reptilia: Chelonidae) en estanques artificiles en Costa Rica / Growth, food conversion and mortality of Eretmochelys imbricata (Reptilia: Chelonidae) en estanques artificiales en Costa Rica

Growth rates, feed conversion and mortality of cultured Eretmochelys imbricata (hawksbill turtle) were studied in concrete raceways by feeding with fresh fish meal (tilapia) and in duplicate (tanks of 21 m2). The turtles were 11 months old at the beginning of the experiment, with and average caparace straight length of 23.64 +/- 1.94 cm, an average caparace curved length of 24.15 +/- 1.94 cm and an average weight of 1527 +/- 2.54 g. The experiment was carried out during six months and a density of 3 ind/m2 was used. The equation of Von Bertalanffy for the growth of E. imbricata was LRC = 3.5 + [(82.0 -3.5)(1-e-0.67432 (t))]. The relationship between caparace straight length-weight was W = 5.207 x 10(-3) LRC 3.8807 (r = 0.99). The feed conversion was 1.54 +/- 0.74 and the mortality was zero during the study