ABSTRACT
This study aimed to report the sanitary conditions through the hematological analysis of grouper E. itajara reared in captivity on estuarine conditions. Seven Goliath groupers (1,881.5±1,246.03g) were captured and kept in two tanks located on estuary. After 20 days, fish were collected for morphologic and hemato-physiologic evaluation. Two fish had clinical signs such as hemorrhagic spots and loss of scale due to agonistic behavior. Blood samples were collected, and the hematological parameters (biochemical, erythrogram and leukogram) were determined. Blood cells were characterized by their size, color and shape. Univariate statistic and principal components analysis were used to identify a hematological standard between fish with or without clinical signs. Four leukocyte types were found: lymphocyte, monocyte, neutrophil and basophil. Regardless of the clinical signs the cell morphology did not present any difference among the fish. However, there is a significant correlation between erythrocyte and lactate on fish with clinical signs. Thus, agonistics encountered among the fish is a stressing factor in captivity conditions making it necessary to have adequate management related to the size of fish and stocking density.(AU)
Este estudo avaliou as condições sanitárias do peixe mero E. itajara mantido sob cativeiro, em condições estuarinas, pelas análises hematológica e morfológica. Sete peixes (1.881,5±1.246,03g) foram capturados e mantidos em tanques localizados no estuário. Após 20 dias, os peixes foram coletados para avaliações morfológica e hematológica. Dois peixes tiveram sinais clínicos, como manchas hemorrágicas e perda de escamas devido ao comportamento agonístico entre os peixes. Amostras sanguíneas foram coletadas dos peixes anestesiados com auxílios de seringas umedecidas com EDTA 3%. Determinaram-se os parâmetros hematológicos (bioquímico, eritrograma e leucograma). Células sanguíneas foram caracterizadas por seu tamanho, cor e padrão. Estatística univariada e análises de componentes principais foram usadas para identificar um padrão hematológico entre os peixes com e sem sinais clínicos. Quatro tipos de leucócitos foram encontrados: linfócito, monócito, neutrófilo e basófilo. Os sinais clínicos não apresentaram diferença entre os peixes e a morfologia celular. Contudo, observou-se uma correlação entre os peixes com sinais clínicos e a quantidade de eritrócitos e lactato. Assim, encontros antagônicos entre os peixes são um fator estressante em condições de cativeiro, tornando-se necessário um manejo mais adequado relacionado ao tamanho dos indivíduos e à densidade de estocagem.(AU)
Subject(s)
Animals , Perciformes , Erythrocyte Count/veterinary , Hematologic Tests/veterinary , Leukocyte Count/veterinary , Stress, PsychologicalABSTRACT
OBJECTIVE@#To develop the rapid and efficient quantitative detection tool for nervous necrosis virus isolated from sevenband grouper Hyporhodus septemfasciatus.@*METHODS@#The viral genes of the NNV (SGYeosu08) isolated from sevenband grouper were phylogenetically analyzed. In addition, novel quantitative PCR primers based on the genomic sequence of SGYeosu08 isolate were designed and compared it with the conventional bio-assay method (TCID50) using in vitro and in vivo samples.@*RESULTS@#The phylogenetic analysis of viral genes demonstrated the relationship of SGYeosu08 with members of red-spotted grouper nervous necrosis virus (RGNNV). The qNNV_R1 primer set (R1_F and R1_R) and the qNNV_R2 primer set (R2_F and R2_R) revealed 93% primer efficiency (regression: y = -0.2861x + 9.9401, R(2) = 0.9976) and the revealed 108% primer efficiency (regression: y = -0.3172x + 10.0611, R(2) = 0.9982), respectively. Its comparison with viral infectivity calculated by TCID50 method showed similar kinetic pattern at in vitro and NNV challenged fish (in vivo) samples.@*CONCLUSIONS@#Result show that this method is rapid and efficient to diagnose NNV infection compare to traditional bioassay method (TCID50).
ABSTRACT
Objective To develop the rapid and efficient quantitative detection tool for nervous necrosis virus isolated from sevenband grouper Hyporhodus septemfasciatus. Methods The viral genes of the NNV (SGYeosu08) isolated from sevenband grouper were phylogenetically analyzed. In addition, novel quantitative PCR primers based on the genomic sequence of SGYeosu08 isolate were designed and compared it with the conventional bio-assay method (TCID
ABSTRACT
Growth stanzas or abrupt changes in growth rates are present throughout the life span of fish. Identifying growth stanzas will help to adequately described growth taking into account that fishes are indeterminate growers. In this study, we used length-weight (L-W) relationships to analyze the growth stanzas in the Grouper-Snapper complex of Southern Gulf of Mexico. For this, the type of sexuality, sex and different sexual maturity phase were considered in the analyses of three species of gonochoric Snappers (Lutjanidae) and six species of protogynous hermaphrodite Groupers (Epinephelidae). Welch ANOVA tests were carried out to determine the existence of differences in length and weight between juveniles and adults per sex. According to the observed differences, L-W relationship parameters (a and b), standard error (SE b) and coefficients of determination (R2) were calculated for all species separately by sex and sexual maturity phase. Snappers’ juvenile-females b-value ranged from 2.44-2.77, juvenile-males from 2.16-2.94, adult-females from 2.63-2.80 and adult-males from 2.63-2.98. Groupers’ b-value ranged for juvenile-females 2.66-3.20, adult-females from 2.73-3.31 and for adult-males 2.93-3.29. For each relationship b-value was t-tested (t-Student) to explore differences from the allometric coefficient (b=3), which indicated changes in body form. Hypothesis test, for regression slopes (b) between Snappers’ juvenile-females vs. adult-females and juvenile-males vs. adult-males and Groupers’ juvenile-females vs. adult-females and adult-females vs. adult-males, indicated different growth stanzas related to gonadal development for Snappers, and to gonadal development and sex change in Groupers. The identification of growth stanzas is crucial to avoid an overestimation or misleading growth rate which is used in fisheries management to establish some target reference points, such as maximum sustainable yield or yield-per-recruit.
Distintos estados o estanzas de crecimiento descritos por cambios en el ritmo de crecimiento, se pueden observar en peces a lo largo de su vida ya que presentan crecimiento indeterminado. A través del análisis de relaciones longitud-peso (L-P), se identificaron distintas estanzas de crecimiento considerando el tipo de sexualidad, sexo y madurez sexual de individuos de tres especies de pargos (Lutjanidae) gonocóricos y seis de meros (Epinephelidae) hermafroditas protóginos. Pruebas independientes de ANOVA de Welch se aplicaron para conocer si existían diferencias estadísticas significativas en la media de la longitud y peso de juveniles, adultos, hembras y machos de pargos y en juveniles hembras, hembras y machos de meros. De acuerdo a las diferencias observadas, se procedió al cálculo de la relación L-P, parámetros a y b, error estándar (SE b) y coeficiente de determinación (R2) por separado (juveniles, adultos, hembras y machos) para cada especie. Los valores del parámetro b para todas las especies se encontraron dentro del rango esperado de 2.5 a 3.5 para pendientes de la relación L-P en peces. Los pargos tuvieron valores de b: juveniles de hembras de 2.44-2.77, juveniles de machos 2.16-2.94, hembras adultas 2.63-2.80 y machos adultos 2.63-2.98. Los meros tuvieron un valor de b para juveniles de hembras: 2.66-3.20, adultos hembras: 2.73-3.31 y adultos de machos: 2.93-3.29. Para cada relación, el valor de b fue probado a través de una prueba de t-Student para explorar diferencias significativas del coeficiente alométrico (b=3), lo cual indicaría cambios en la forma del cuerpo de los individuos. Finalmente pruebas de hipótesis sobre las diferencias entre pendientes obtenidas de las relaciones L-P mostraron distintas estanzas de crecimiento relacionadas en pargos con el desarrollo gonadal y en meros con el desarrollo gonadal pero también con el cambio de sexo. A través de este estudio se pudo observar la existencia de distintas estanzas de crecimiento en especies de alta importancia comercial para el Sur del Golfo de México. Por lo tanto se recomienda la obtención de las relaciones L-P por separado según el sexo y desarrollo gonadal de cada especie, para evitar una sobre estimación o un cálculo erróneo de la tasa de crecimiento poblacional la cual se utiliza en manejo de las pesquerías para determinar algunos puntos de referencia como el criterio de máximo rendimiento sostenible o bien el criterio de rendimiento por recluta.
Subject(s)
Animals , Female , Male , Body Size , Body Weight , Gonads/growth & development , Perciformes/growth & development , Sexual Maturation , Mexico , Perciformes/classificationABSTRACT
In this study we analyze the population structure and diet of the coney Cephalopholis fulva at Trindade Island, Brazil, through direct observation with SCUBA diving in 11 reef sites around the Island, up to 50 m deep. Diet was based on 77 individuals collected with speargun. Mean population density and biomass were estimated at 29 individuals/100 m² and 13 kg/100 m², respectively. This species is regularly distributed along the costal environments of the Trindade Island, with no significant differences in densities and biomass detected among the different collection habitats (reef crest, reef slope, and reef plateau). However, significantly higher densities were observed micro-habitats with greater structural complexity, which may offer more shelter and food to C. fulva. Four food item groups were identified from the gut contents of C. fulva: Annelida, Crustacea, Teleostei, and Testudinata. It is the first record of predation of the green turtle Chelonia mydas hatchlings by the coney. Trindade Island seems to present the densest concentration of C. fulva in all Brazilian and Caribbean ecosystems inhabited by this species. Scarcity of competitors, predators, and fishing pressure may explain the high densities observed in the Island.
Foram analisadas a estrutura populacional e a dieta do catuá Cephalopholis fulva na Ilha da Trindade, Brasil. Os dados foram obtidos através de censos visuais com mergulho autônomo em 11 locais no entorno da ilha, em profundidades de até 50 m. A dieta e a proporção sexual foram baseadas na análise de 77 indivíduos coletados com arpão. A densidade populacional e biomassa foram estimados em 29 indivíduos/m² e 13 kg/100 m², respectivamente. A espécie apresentou distribuição uniforme nos ambientes costeiros da ilha, não tendo sido registradas diferenças significativa em sua densidade e biomassa entre os diferentes habitats estudados (crista, talude e platô recifal). Entretanto, foi observado preferência por micro-habitats de alta complexidade estrutural. Foram registrados quatro grupos de itens alimentares no conteúdo estomacal de C. fulva: Annelida, Crustacea, Teleostei e Testudinata. É feito aqui o primeiro registro de predação de juvenis da tartaruga-verde (Chelonia mydas) por C. fulva. Trindade parece apresentar os maiores valores de densidade para o catuá, quando comparada a outras localidades do Brasil e Caribe. A escassez de competidores, predadores e a pressão pesqueira são possíveis fatores que podem explicar as altas densidades observadas para C. fulva na Ilha da Trindade.
Subject(s)
Animals , Biomass , Bass/growth & development , Diet/veterinary , Animal Distribution/classification , Population DensityABSTRACT
A garoupa-verdadeira (Epinephelus marginatus) é uma espécie de serranídeo com grande importância ecológica e boas perspectivas para o cultivo. A investigação da morfologia do trato digestório, associada à atividade alimentar, é fundamental para a compreensão da biologia dessa espécie e premissa básica para pesquisas sobre requerimentos nutricionais, desenvolvimento de rações e práticas adequadas de manejo alimentar. O presente trabalho descreve a anatomia e, por meio da microscopia de luz, as variações histológicas ao longo do tubo digestório de juvenis de Epinephelus marginatus, correlacionando a histologia de cada seguimento com as respectivas funções e o hábito alimentar. Verificou-se que essa espécie possui elevado número de tipos celulares ao longo do tubo digestório que estão intimamente relacionados com a resposta imunológica inata e adaptativa, permitindo o hábito alimentar detritívoro.
The dusky grouper (Epinephelus marginatus) is a serranida species with great ecological importance and good perspectives for rearing. The investigation of the digestive tract morphology associated to the feeding activity is essential for the understanding of the biology of this species and a basic premise for research on feed requirements, feed development and appropriate feeding methods. The present study describes the anatomy and histological variations along the digestive tract of Epinephelus marginatus juveniles associating the histology with function and feeding habit. It was verified that this species possesses a high number of different cellular types along the digestive tube intimately related with the innate and adaptative immunological responses.
Subject(s)
Feeding Behavior , Histology , Marine Environment , BassABSTRACT
The Goliath grouper, Epinephelus itajara, a large-bodied (~ 2.5 m TL, > 400 kg) and critically endangered fish (Epinephelidae), is highly vulnerable to overfishing. Although protected from fishing in many countries, its exploitation in Mexico is unregulated; a situation that puts its populations at risk. Fishery records of E. itajara are scarce, which prevents determination of its fishery status. This work aimed to elucidate the E. itajara fishery in the northern Yucatan Peninsula by 1) analyzing available catch records and 2) interviewing veteran fishermen (local ecological knowledge) from two traditional landing sites: Dzilam de Bravo and Puerto Progreso. Historic fishery records from two fishing cooperatives were analyzed in order to elucidate the current situation and offer viable alternatives for conservation and management. Catches have decreased severely. Local knowledge obtained from fishermen represented a very important source of information for reconstructing the fisheries history of this species. Conservation measures that incorporate regional and international regulations on critically endangered fish species are suggested. Rev. Biol. Trop. 57 (3): 557-566. Epub 2009 September 30.
La cherna, Epinephelus itajara, un mero (Epinephelidae) corpulento (~ 2.5 m TL, > 400 kg) y amenazado, es altamente vulnerable a la sobrepesca. Si bien es protegido en varios países, en México su explotación no está regulada; situación que pone a su población en riesgo. Sus registros pesqueros son escasos, lo que impide determinar su condición pesquera. Este trabajo intentó ilustrar la pesquería en el norte de la Península de Yucatán usando procedimientos que involucraron analizar registros y entrevistar a pescadores veteranos (conocimiento ecológico tradicional) de dos sitios de desembarque: Dzilam de Bravo y Puerto Progreso. Se analizaron registros pesqueros históricos de dos cooperativas pesqueras para determinar la situación actual y ofrecer alternativas viables para conservación y manejo. Las capturas han disminuido drásticamente. El conocimiento local obtenido de los pescadores representa una fuente muy importante de información para ayudar a reconstruir la historia pesquera de esta especie. Se sugieren medidas de conservación que incorporen regulaciones nacionales e internacionales para especies de peces.
Subject(s)
Animals , Humans , Fishes , Fisheries/statistics & numerical data , Conservation of Natural Resources , Environmental Monitoring , Interviews as Topic , Mexico , Population DensityABSTRACT
The Goliath grouper (Epinephelus itajara) is one of the most endangered species of fish of the subfamily Epinephelinae. Slow to develop and mature, and dependent on mangrove habitats for breeding, the species also suffers intense harvesting, which has reduced drastically in numbers in many areas. To contribute to the understanding of the characteristics of E. itajara populations, we conducted a molecular genetics study of the species, focusing on populations from the Northern Brazilian coast. The mtDNA control region (D-loop) of 116 individuals from five localities (Bragança, Ajuruteua, Parnaíba, Fortaleza and Natal) was analysed, and a sequence of 499 base pairs identified. Analyses of the sequences indicated that genetic variability was generally lower in E. itajara than in other endangered species of the genus. AMOVA found no significant grouping structure among the populations. Nested Clade Analysis revealed a significant association between genetic variability and geographic distribution among only three populations (Ajuruteua, Parnaíba and Natal). Genetic diversity was higher in populations from the Amazon region, which may be related to the better conservation of mangrove habitats in this area. Therefore, the present study could be used for the implementation of conservation and management measures in order to protect and consolidate these populations.
Subject(s)
Animals , DNA, Mitochondrial/analysis , Genetics, Population , Fishes/genetics , Brazil , Conservation of Natural Resources , Endangered Species , Genetic VariationABSTRACT
Fishborne zoonotic metacercariae have not been reported from brackish water and marine fish from Vietnam waters although these parasites are common in the country's freshwater fish. Both wild-caught and cultured grouper (Epinephelus coioides and Epinephelus bleekeri), and mullet (Mugil cephalus) from brackish and marine waters locate in Khanh Hoa province in central coastal Vietnam were examined, and found positive for zoonotic trematode metacercariae. From grouper, Heterophyopsis continua and Procerovum varium were recovered. The prevalence of H. continua ranged from 2.0 to 6.0% and that for P. varium ranged from 11.6 to 15.8%. Mullet were infected with Pygidiopsis summa and H. continua both of these species are new records for Vietnam. The prevalence of P. summa in mullet was generally high, ranging from 17.6 to 75.5%, and was significantly higher than the prevalence of H. continua (2.5 to 32.4%). There were no significant differences in the prevalence of metacercariae between grouper from natural or cultured habitats, indicating that the highest risk of infection occurs in the wild-caught state prior to their placement in culture. Further, there was no difference in metacercarial prevalence between the 2 species of grouper. Infected wild-caught seed were only observed from January to October. Monthly variation in prevalence suggests seasonal variation in mullet infections occurs in this region with the highest transmission taking place from October to December. Basic investigations on the ecology and epidemiology of these intestinal flukes need to be carried out to determine their significance as a public health problem and the aspects of their biology that may be vulnerable to control interventions.