The giant freshwater shrimp, Macrobrachium rosenbergii is a large species of prawn grown extensively in aquaculture settings. A social hierarchy exists within the males of this species, representing three distinct male morphotypes. These male morphotypes differ in their behavior, physiology, and morphology and include the largest blue-clawed males (BC males), moderately- sized orange-clawed males (OC males), and the undifferentiated small-clawed males (SM males). All individuals of this species perform grooming behaviors to rid themselves of body fouling which can impede important functions such as movement, respiration, chemoreception, and reproduction. Grooming behaviors in crustaceans often utilize specialized structures called setae, which aid in the removal of fouling material such as debris, algae, and epibionts. The grooming behaviors of M. rosenbergii were examined in this thesis to better understand the importance of these behaviors. Grooming behaviors were commonly seen among all sexes and morphotypes of M. rosenbergii along with other behaviors such as searching for food/habitat, reproductive attempts, and agonistic interactions (N=94). As a species, there were no differences in the regions of the body groomed in terms of frequency and duration. In general, the most commonly used grooming appendage, the first pereopods, and the antennae were most frequently groomed. The antennae are an important site of chemosensory reception and were likely frequently groomed to maintain this sensory input. The internal sites for respiration, the gills, were groomed for the longest amount of time, indicating the importance of removing fouling from these structures. Of the females and male morphotypes, the largest and most dominant BC males performed the most grooming actions and spent the most time grooming, compared to other individuals within the species. This high grooming time budget (35%) is likely due to their position within the social hierarchy; these males must maintain their body along with the structures which allow them to maintain their dominance such as large chelipeds used in territorial interactions with other males. Grooming behaviors in crustaceans were previously hypothesized as secondary behaviors, only occurring when other behaviors were not prioritized. Results from this study provide further evidence of this hypothesis; although grooming is considered an important behavior to remove fouling and prevent interruptions in functions such as respiration, locomotion, and reproduction, it’s frequency and duration decreases when other behaviors prove more beneficial. Results from this thesis continue to validate the adaptive value of grooming in the changing environmental conditions crustaceans experience on a daily basis. These behaviors remove fouling from the body and promote locomotion, respiration, chemoreception, and reproduction. In addition, shrimps grown in aquaculture settings may experience increased fouling when in grow-out ponds. This increased exposure to fouling organisms and debris may lead to an increased mortality of profitable shrimps. Understanding the fouling pressures and grooming abilities of these shrimps during vulnerable times such as placement in grow-out ponds and intermolt periods may increase yield and profitability for aquaculture farmers.

Hawaiian red shrimp - Halocaridina rubra (order Decapoda; family Atyidae) is an endemic species originated from Hawaii Islands. It is adapted to a specific environment of underground systems and anchialine pools. Halocaridina rubra has a great potential for aquarium shrimps breeders as well as for researchers. The aim of this work was to: (1) document the reproduction of shrimp Halocaridina rubra and (2) determine the influence of selected chronobiological factors and presence/absence of a shelter for its reproduction. The experiment was realized in the aquarium room and chronobiological laboratory at the department of Biological disciplines at the Faculty of Agriculture, University of South Bohemia in České Budějovice. The experiment took three months (i.e. from 3 rd November 2014 to 3 rd February 2015). This experiment had 4 treatments each with two repetitions: on the light with and without a shelter, in the dark with and without a shelter. Experimental shrimps were put into the aquaria in the breeding groups: 10: 16 (female: male). The frequency of mating was evaluated. Neither the light conditions (12 h (light): 12 h (dark) or permanent dark) nor the presence of shelter had impact on the reproduction of Halocaridina rubra. The reproduction of shrimp Halocaridina rubra was documented. Spermatophore transfer, eggs, four larval stages of zoea type, megalopal stage and two juvenil stages are monitored. Recommendations for breeding have been developed. Anesthesia was tested by using eugenol (clove oil) in shrimps.

Made available in DSpace on 2014-06-11T19:35:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-09-24Bitstream added on 2014-06-13T20:07:15Z : No. of bitstreams: 1 almeida_ac_dr_botib.pdf: 859822 bytes, checksum: c0f964299ecfb510e7f66b1eea006b46 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / The spatial and temporal patterns of abundance and distribution of Xiphopenaeus kroyeri and its relationship with several environmental variables were compared over a range of 20 years. The abiotic and biotic data set were obtained monthly during two distinct study periods; period 1, from November 1988 to October 1989; and period 2, from November 2008 to October 2009, in seven permanent transects established within Fortaleza Bay, on the southeastern coast of Brazil. A remarkable sedimentation was observed between the first and the second study periods, which might have been caused by natural phenomena and/or human activities. While the variations in the bottom temperature and salinity were related mainly to the hydrodynamics of water masses present in the Ubatuba region. The abundance of X. kroyeri increased considerably over a range of 20 years. A total of 13 298 and 39 553 specimens were obtained throughout the sampling periods 1 and 2, respectively. The total abundance of the species and the abundance of males and females differed spatially, while the abundance of juveniles differed seasonally, during each study period (ANOVA, p < 0.05). Overall, the highest abundance of the species was recorded in those transects which the sediment was composed mainly by fine and very fine sand and silt and clay. The presence of algae and plant floating near the marine floor at Fortaleza Bay also favored the occurrence and settlement of X. kroyeri. Interestingly, during period 1 the species was most abundant in winter, when bottom temperature reached low mean value (21.6°C). While during period 2, the highest abundance of X. kroyeri was obtained in summer and fall. Concomitantly, the highest mean values of bottom temperature were recorded during these seasons (25.2 and 24.5°C, respectively). So, the... (Complete abstract click electronic access below)

Orientador: Marcelo Antonio Amaro Pinheiro / Coorientador: Patricio Alejandro Hernáez Bové / Resumo: As praias de Santos (SP) apresentam legislação municipal de proibição de captura das espécies de Callianassidae, p ex. Callichirus major (Lei Municipal nº 1.293/93), fato este não verificado em municípios limítrofes, como São Vicente. Esta legislação foi decorrente de um amplo estudo de 10 anos (1983 a 1993), desde então não existindo outros mais aprofundados sobre a biologia populacional desta espécie. Portanto, a presente dissertação tem como objetivos realizar uma avaliação comparativa da biologia populacional de Callichirus major entre a praia do Gonzaga, localizada no Município de Santos (protegida) e a praia do Itararé, no Município de São Vicente (sem legislação pertinente à captura da espécie). O primeiro objetivo foi efetuar um teste de tamanho do quadrado ideal para as amostragens, através do método de Wigert (W), assim como o número de réplicas por subárea amostral, determinada pela estabilização das variâncias (V), indicando um mínimo ideal de 50 réplicas (V=24,6). O possível efeito da declividade e distância do mar sobre os parâmetros populacionais da espécie foi também testado em duas transecções de quadrados amostrais contíguos (vertical e paralela à linha de costa). Com base nos resultados obtidos, foi estabelecido o número de subáreas amostrais em cada praia, levando-se em conta sua extensão (Praia do Itararé: 2,3 km; e Praia de Santos: 4,7 km). A densidade foi maior nas transecções próximas aos canais (5,0 ± 1,6 e 4,5 ± 2,0 ind./m2) do que aquela mais equidi... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The C. major from Santos (SP) are protected by law (municipal law number 1.293/93) so, it's prohibited to capture this crustacean from the beaches, this fact isn't verified at boundaries counties, just like São Vicente, for example. This legislation was due a great study during 10 years (1983 to 1993), since then, doesn't exist other importants studies about this specie. Therefore, this present dissertation aims to realize a comparative avaliation of the populational biology of Callichirus major between Gonzaga beach (Santos, SP), a protected area, and Itararé beach (São Vicente, SP). The first objective was realize a test to obtain a optimiun quadrat size for the sampling, using the Wigert (W) method, as well as the number of replicates per sample areas, determinate by the stabilization of variances (V), indicating a minimum of 50 replicas (V=24,6). The possible effect of declivity and sea's distance were evaluated too, using for this, two transections of contiguous sample quadrat (vertical and parallel to the coast line), the one with less variance of sazonal and temporal analyzes was chosen. Based in the obtained results, a number of sample areas were established, taking into account the beaches's extension (Itararé's beach: 2,3km; Santos's beach: 4,7 km). The density was bigger at the transections near the channels (5,0 ± 1,6 e 4,5 ± 2,0 ind./m2) then the equidistant one (F = 13,20; p = 0,000), indicating to avoid nearby channels areas to minimize the sampling bias during the spatial analyzes. In both beaches the species's galleries per sample quadrat were calculated, in order to compare the distribution conditions of this animal particularly at these beaches, and the respective data inserted in eletronics spreadsheets, reaching the second objective os this study. In other subarea, at both beaches (Gonzaga e Itararé), specimens of C. major... (Complete abstract electronic access below) / Mestre

Made available in DSpace on 2016-09-27T13:40:09Z (GMT). No. of bitstreams: 0 Previous issue date: 2003-02-25. Added 1 bitstream(s) on 2016-09-27T13:45:23Z : No. of bitstreams: 1 000200251.pdf: 247089 bytes, checksum: 2912bb4042b02ccf2ea439da58071d14 (MD5) / Este trabalho teve como objetivo avaliar a vida útil do camarão de água doce Macrobrachium rosenbergii armazenado descabeçado em gelo durante 14 dias, comparando duas condições de armazenamento: CCG - camarões armazenados em contato direto com o gelo e SCG - sem contato com gelo (camarões em sacos plásticos mantidos em gelo). A vida útil foi monitorada por meio de análises químicas como nitrogênio não protéico (NNP), bases nitrogenadas voláteis (BNV), TBA, determinação do pH, e também por análises microbiológicas e sensoriais. Foram realizadas amostragens em intervalos de tempo aos 0, 2, 4, 7, 10 e 14 dias de estocagem. Os teores iniciais de BNV de 18,75 mg de N/100g de amostra atingiram 21,73 mg N/100g no tratamento SCG e 5,47 mg de N/100g no tratamento CCG após 14 dias de estocagem. Os teores de NNP para o tratamento SCG aumentaram de 436,99 mg de N/100g no dia zero para 542,30 mg de N/100g no final do armazenamento. No tratamento CCG, os teores de NNP diminuíram até o final do experimento (436,99 a 158,24 mg de N/100g). Os valores de TBA aumentaram no tratamento SCG ao longo da estocagem (0,08 a 1,83 mg de malonaldeído/kg) e mantiveram-se constantes no tratamento CCG (0,08 mg de malonaldeído/kg para 0,18 mg de malonaldeído/kg). Os dois tratamentos tiveram o mesmo comportamento quanto ao pH, mantendo-se constantes durante toda a estocagem. As contagens de coliformes fecais e totais mantiveram-se dentro dos níveis de aceitação em ambos os tratamentos. A contagem inicial de psicrotróficos foi de log 2,32 UFC/g para os dois experimentos, verificando-se, posteriormente um aumento de cerca de duas casas logarítmicas para o tratamento SCG e três unidades logarítmicas por grama de tecido para o tratamento CCG. Na análise sensorial os provadores não constataram alterações de sabor até o 10o dia de estocagem, nos camarões do tratamento SCG, detectando porém queda... / The objective of the present work was to evaluate the shelf-life of the freshwater prawn Macrobrachium rosenbergii deheaded, shelled and stored in ice during 14 days. Two storage conditions were compared: DIC - prawn storage with direct ice contact and WIC - prawns without ice contact (specimens packed in polyethylene bags). The shelflife was evaluated by chemical analysis, namely: non-protein nitrogen (NPN), total volatile base nitrogen (TVB-N), rancidity (TBA), pH; and also by microbiological and sensorial analysis. Samples were collected at 0, 2, 4, 7, 10, and 14 days of storage. TVB-N initial contents (18.75 mg N/100g sample) reached 21.73 mg N/100g in WIC treatment and 5.47 mg N/100g in DIC treatment after 14 days of storage. NNP contents in WIC treatment increased from 436.99 mg N/100g at day zero to 542.30 mg N/100g in the end of storage. In DIC treatment, NNP contents decreased until the last day of this study (from 436.99 to 158.24 mg N/100g). TBA values increased in WIC treatment along of storage (from 0.08 to 1.83 mg of malonaldehyde/kg) and remained approximately constant in DIC treatment (from 0.08 mg to 0.18 of malonaldehyde/kg). Also for both treatments the pH was observed to remain constant during the whole storage time. Total and faecal coliforms countings were within the acceptable levels in both treatments. The initial psychrotrophic counting scored log 2.32 CFU/g for both experiments; at the end of the storage we observed an increase of about two logarithmic units/g for WIC treatment and of three logarithmic units/g for DIC treatment. Regarding the sensorial analysis, the assessors observed no changes in flavour until the 10th storage day for prawns in WIC treatment. At the 14th day, a decrease in quality (P < 0.05) was detected. In DIC treatment, however, flavour scores continuously decreased (P < 0.05) during the storage, reaching an average value of 4 in a scale from ...

Made available in DSpace on 2016-09-27T13:40:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2003-01-31. Added 1 bitstream(s) on 2016-09-27T13:45:25Z : No. of bitstreams: 1 000200264.pdf: 1024800 bytes, checksum: 0a482dbcd13b6325f19b44716edf1302 (MD5) / Avaliou-se a influência dos ácidos graxos, poli-insaturados (n-3 HUFA e 18:2n-6) sobre os índices gonadossomático, hepatossomático e a fecundidade de fêmeas da espécie Macrobrachium amazonicum. Para tanto, três grupos de 24 fêmeas foram alimentadas com rações isoproteicas e isolipídicas contendo diferentes níveis dos ácidos graxos n-3 HUFA e 18:2n-6 (12mg/g de ração) para T1, n-3 HUFA (6mg/g de ração) e 18:2n-6 (12mg/g de ração) para T2 e n-3 HUFA e 18:2n-6 (6mg/g de ração) para T3. As coletas iniciaram-se após 45 dias de experimento estando de acordo com o estágio ovariano I,III e V. Após biometria, os ovários e o hepatopâncreas foram coletados e pesados individualmente. Os dados foram correlacionados para obtenção dos índices hepatossomático (IHS) e gonadossomático (IGS). A análise da fecundidade foi obtida com a coleta de ovos fecundos e determinada a partir de relações: número de ovos/tamanho do animal, número de ovos/peso do animal e número de ovos/tamanho da carapaça. Observou-se também o tamanho dos ovos nos diferentes tratamentos. A análise estatística dos dados, quanto ao IGS, demonstrou diferenças significativas somente para ovários de fêmeas em estágio V alimentadas com o T2. A análise do IHS demonstrou não haver interação entre tratamentos. A diferença para este índice ocorreu entre os estágios de maturação. Em relação à fecundidade, fêmeas provindas do T2 apresentaram maior número de ovos e conseqüentemente maior fecundidade. Os resultados indicaram que baixas concentrações de n-3 HUFA e altas concentrações de ácido linoleico (18:2n-6), contribuíram para melhor potencial reprodutivo do órgão proporcionando gônada mais pesada em relação às dos demais tratamentos, além de aumentar a fecundidade demonstrada a partir do aumento do número de ovos para fêmeas do T2

Made available in DSpace on 2016-09-27T13:40:13Z (GMT). No. of bitstreams: 0 Previous issue date: 2001. Added 1 bitstream(s) on 2016-09-27T13:45:34Z : No. of bitstreams: 1 000138726.pdf: 935379 bytes, checksum: 4693a0d5cee75f852ec144c7ee2d5f32 (MD5) / A freqüência de aceitação de alimento (FAA) por larvas de M. rosenbergii foi utilizada como medida para determinar o tamanho de partícula e o tipo de alimento mais adequados para cada estágio de desenvolvimento. Foram testados quatro classes de tamanho de partículas (250-425; 425-710; 710-1000 e 1000-1190 mm) de dois tipos de ração (seca e úmida). Verificou-se também a freqüência de aceitação das duas rações e de náuplios de Artemia em cada estágio larval. A freqüência de aceitação foi obtida pela avaliação qualitativa da ingestão de cada alimento pelas larvas por meio da observação do trato digestório das mesmas sob estereomicroscópio. Não houve relação significativa (P < 0,01) entre o tamanho das partículas na freqüência de aceitação das rações pelas larvas no decorrer do desenvolvimento. Náuplios de Artemia foram significativamente mais ingeridos por larvas entre os estágios II e VII; aceitação similar para a ração úmida e seca foi obtida a partir dos estágios VII e IX, respectivamente. Verificou-se que o alimento inerte foi capturado e ingerido por mais de 50% das larvas apenas a partir dos estágios VII (ração úmida) e VIII (ração seca). Nossos resultados indicam que a complementação da dieta com alimento inerte deve se iniciar a partir do estágio VII / The functional response (relationship between ingestion rate and food concentration) was determined for each larval stage of Macrobrachium rosenbergii. Artemia nauplii were supplied at six different densities: 2, 4, 6, 8, 10 and 12 ind/mL. The nauplii were counted manually using a Pasteur pipette and placed in Petri dishes containing 40 mL of brackish water (12‰). A single Macrobrachium rosenbergii larvae was placed in each Petri dish and after 24 hours the leftover nauplii were counted. Daily average ingestion rate by larva was calculated for each zoeal stage. Consumption pattern was defined by the model I = Im(1-e-kP). Ingestion rate increased with food density in the medium. The best relationship between predator and prey seemed to occur during stages IV and V. The high values for maximum ingestion (Im) and the low values for constant k obtained in the last larval stages indicate the necessity of supplementary diet during the final stages of development

Orientador: Elisabete Maria Macedo Viegas / Banca: Wagner Cotroni Valenti / Banca: Rose Meire Vidotti / Resumo: Este trabalho teve como objetivo avaliar a vida útil do camarão de água doce Macrobrachium rosenbergii armazenado descabeçado em gelo durante 14 dias, comparando duas condições de armazenamento: CCG - camarões armazenados em contato direto com o gelo e SCG - sem contato com gelo (camarões em sacos plásticos mantidos em gelo). A vida útil foi monitorada por meio de análises químicas como nitrogênio não protéico (NNP), bases nitrogenadas voláteis (BNV), TBA, determinação do pH, e também por análises microbiológicas e sensoriais. Foram realizadas amostragens em intervalos de tempo aos 0, 2, 4, 7, 10 e 14 dias de estocagem. Os teores iniciais de BNV de 18,75 mg de N/100g de amostra atingiram 21,73 mg N/100g no tratamento SCG e 5,47 mg de N/100g no tratamento CCG após 14 dias de estocagem. Os teores de NNP para o tratamento SCG aumentaram de 436,99 mg de N/100g no dia zero para 542,30 mg de N/100g no final do armazenamento. No tratamento CCG, os teores de NNP diminuíram até o final do experimento (436,99 a 158,24 mg de N/100g). Os valores de TBA aumentaram no tratamento SCG ao longo da estocagem (0,08 a 1,83 mg de malonaldeído/kg) e mantiveram-se constantes no tratamento CCG (0,08 mg de malonaldeído/kg para 0,18 mg de malonaldeído/kg). Os dois tratamentos tiveram o mesmo comportamento quanto ao pH, mantendo-se constantes durante toda a estocagem. As contagens de coliformes fecais e totais mantiveram-se dentro dos níveis de aceitação em ambos os tratamentos. A contagem inicial de psicrotróficos foi de log 2,32 UFC/g para os dois experimentos, verificando-se, posteriormente um aumento de cerca de duas casas logarítmicas para o tratamento SCG e três unidades logarítmicas por grama de tecido para o tratamento CCG. Na análise sensorial os provadores não constataram alterações de sabor até o 10o dia de estocagem, nos camarões do tratamento SCG, detectando porém queda... / Abstract: The objective of the present work was to evaluate the shelf-life of the freshwater prawn Macrobrachium rosenbergii deheaded, shelled and stored in ice during 14 days. Two storage conditions were compared: DIC - prawn storage with direct ice contact and WIC - prawns without ice contact (specimens packed in polyethylene bags). The shelflife was evaluated by chemical analysis, namely: non-protein nitrogen (NPN), total volatile base nitrogen (TVB-N), rancidity (TBA), pH; and also by microbiological and sensorial analysis. Samples were collected at 0, 2, 4, 7, 10, and 14 days of storage. TVB-N initial contents (18.75 mg N/100g sample) reached 21.73 mg N/100g in WIC treatment and 5.47 mg N/100g in DIC treatment after 14 days of storage. NNP contents in WIC treatment increased from 436.99 mg N/100g at day zero to 542.30 mg N/100g in the end of storage. In DIC treatment, NNP contents decreased until the last day of this study (from 436.99 to 158.24 mg N/100g). TBA values increased in WIC treatment along of storage (from 0.08 to 1.83 mg of malonaldehyde/kg) and remained approximately constant in DIC treatment (from 0.08 mg to 0.18 of malonaldehyde/kg). Also for both treatments the pH was observed to remain constant during the whole storage time. Total and faecal coliforms countings were within the acceptable levels in both treatments. The initial psychrotrophic counting scored log 2.32 CFU/g for both experiments; at the end of the storage we observed an increase of about two logarithmic units/g for WIC treatment and of three logarithmic units/g for DIC treatment. Regarding the sensorial analysis, the assessors observed no changes in flavour until the 10th storage day for prawns in WIC treatment. At the 14th day, a decrease in quality (P < 0.05) was detected. In DIC treatment, however, flavour scores continuously decreased (P < 0.05) during the storage, reaching an average value of 4 in a scale from ... / Mestre

Orientadora: Irene Bastos Franceschini Vicentini / Banca: Luiz Edivaldo Pezzato / Banca: Maíra Aparecida Stefanini / Resumo: Avaliou-se a influência dos ácidos graxos, poli-insaturados (n-3 HUFA e 18:2n-6) sobre os índices gonadossomático, hepatossomático e a fecundidade de fêmeas da espécie Macrobrachium amazonicum. Para tanto, três grupos de 24 fêmeas foram alimentadas com rações isoproteicas e isolipídicas contendo diferentes níveis dos ácidos graxos n-3 HUFA e 18:2n-6 (12mg/g de ração) para T1, n-3 HUFA (6mg/g de ração) e 18:2n-6 (12mg/g de ração) para T2 e n-3 HUFA e 18:2n-6 (6mg/g de ração) para T3. As coletas iniciaram-se após 45 dias de experimento estando de acordo com o estágio ovariano I,III e V. Após biometria, os ovários e o hepatopâncreas foram coletados e pesados individualmente. Os dados foram correlacionados para obtenção dos índices hepatossomático (IHS) e gonadossomático (IGS). A análise da fecundidade foi obtida com a coleta de ovos fecundos e determinada a partir de relações: número de ovos/tamanho do animal, número de ovos/peso do animal e número de ovos/tamanho da carapaça. Observou-se também o tamanho dos ovos nos diferentes tratamentos. A análise estatística dos dados, quanto ao IGS, demonstrou diferenças significativas somente para ovários de fêmeas em estágio V alimentadas com o T2. A análise do IHS demonstrou não haver interação entre tratamentos. A diferença para este índice ocorreu entre os estágios de maturação. Em relação à fecundidade, fêmeas provindas do T2 apresentaram maior número de ovos e conseqüentemente maior fecundidade. Os resultados indicaram que baixas concentrações de n-3 HUFA e altas concentrações de ácido linoleico (18:2n-6), contribuíram para melhor potencial reprodutivo do órgão proporcionando gônada mais pesada em relação às dos demais tratamentos, além de aumentar a fecundidade demonstrada a partir do aumento do número de ovos para fêmeas do T2 / Abstract: Not available / Mestre

Orientador: Adilson Fransozo / Banca: Roberto Munehisa Shimizu / Banca: Fúlvio Aurélio de Moraes Freire / Banca: Gustavo Monteiro Teixeira / Banca: Rogério Caetano da Costa / Resumo: Não disponível / Abstract: The spatial and temporal patterns of abundance and distribution of Xiphopenaeus kroyeri and its relationship with several environmental variables were compared over a range of 20 years. The abiotic and biotic data set were obtained monthly during two distinct study periods; period 1, from November 1988 to October 1989; and period 2, from November 2008 to October 2009, in seven permanent transects established within Fortaleza Bay, on the southeastern coast of Brazil. A remarkable sedimentation was observed between the first and the second study periods, which might have been caused by natural phenomena and/or human activities. While the variations in the bottom temperature and salinity were related mainly to the hydrodynamics of water masses present in the Ubatuba region. The abundance of X. kroyeri increased considerably over a range of 20 years. A total of 13 298 and 39 553 specimens were obtained throughout the sampling periods 1 and 2, respectively. The total abundance of the species and the abundance of males and females differed spatially, while the abundance of juveniles differed seasonally, during each study period (ANOVA, p < 0.05). Overall, the highest abundance of the species was recorded in those transects which the sediment was composed mainly by fine and very fine sand and silt and clay. The presence of algae and plant floating near the marine floor at Fortaleza Bay also favored the occurrence and settlement of X. kroyeri. Interestingly, during period 1 the species was most abundant in winter, when bottom temperature reached low mean value (21.6°C). While during period 2, the highest abundance of X. kroyeri was obtained in summer and fall. Concomitantly, the highest mean values of bottom temperature were recorded during these seasons (25.2 and 24.5°C, respectively). So, the... (Complete abstract click electronic access below) / Doutor