Rossineide Martins da Rocha

Seasonal changes in the gonadossomatic index, allometric condition factor and sex ratio of an auchenipterid catfish from eastern Amazonia

The aim of the present study was to evaluate the seasonal pattern of the gonadosomatic index (GSI), condition factor (K), and sex ratio in the catfish Auchenipterichthys longimanus (Siluriformes: Auchenipteridae) as an approach to identify its reproductive period. A total of 589 A. longimanus specimens (251 males and 338 females) were captured in the rivers of the Caxiuana National Forest, in the Brazilian state of Para, between July, 2008 and July, 2009. Among the male specimens, 171 were classified as adults and 80 as juveniles, while there were 249 adults and 89 juvenile females. Using a sinusoidal equation, analysis of the GSI revealed a reproductive asynchrony between the genders, with males attaining their highest GSI values in January, while females peaked in March. For males, the sinusoidal regression for GSI values was significant only when used the complete data set (P=0.001), wears no trend was identified for bimonthly means (P=0.136). For females, by contrast, significant values were obtained for both the complete data set (P=0.012) and bimonthly GSI means (P=0.026). For the condition factor, the sinusoidal equation returned significant seasonal variation in both raw data (P=0.02) and with mean values (P=0.00) for males, but only with raw data for females (P=0.04), which appears to reflect variation in the energy budget between genders. With regard to the sex ratio, more reproductive females were captured than males in January and March, 2009, which suggests a pattern of segregation related to the reproductive process. These parameters are fundamental to the assessment, protection, and management of natural fish stocks, as well as providing guidelines for the development of conservation strategies.

Reproductive biology of Plagioscion magdalenae (Teleostei: Sciaenidae) (Steindachner, 1878) in the bay of Marajo, Amazon Estuary, Brazil

Plagioscion magdalenae (pescada-curuca) e um sciaenideo bentopelagico, de importância comercial, amplamente distribuido na bacia do rio Amazonas. O objetivo deste trabalho foi descrever a biologia reprodutiva dessa especie na baia do Marajo, estuario Amazonico, Brasil. Neste estudo foi determinado o estadio do desenvolvimento gonadal, tamanho de primeira maturacao gonadal (L50), proporcao entre sexos, epoca e o tipo de desova. A coleta foi realizada bimestralmente no periodo de dezembro de 2005 a outubro de 2006. Foi examinado um total de 251 exemplares, variando entre 220 e 590 mm de comprimento total (CT). A relacao peso-comprimento para femeas, machos e sexos agrupados foi altamente significativa, com alometria positiva. O L50 foi de 279 mm considerando sexos agrupados, 305 e 269 mm CT para femeas e machos respectivamente. A proporcao entre sexos para o total de individuos foi favoravel aos machos (2,02 machos: 1 femea). Macroscopicamente, as gonadas foram classificadas em imatura, em maturacao, matura e desovada. Considerando-se as avaliacoes macro e microscopicas das gonadas, foi registrado um periodo prolongado de desova, principalmente entre agosto e fevereiro.

Gonadal development in the freshwater crab Sylviocarcinus pictus (H. Milne Edwards, 1853) (Brachyura: Trichodactylidae) from the Guamá river, state of Pará, Brazil

The development stages of male and female gonads in the freshwater crab Sylviocarcinus pictus (H. Milne Eduards, 1853) were described through macroscopic and microscopic (histology) examinations. The histological description was based on 40 specimens (20 each sex). Four gonadal development stages were found for females: immature, ripening, mature and spawned. The following female cells were found: ovogonia, oocytes in initial vitellogenesis, oocytes in advanced vitellogenesis, follicular cells and post-ovulatory follicles. Three development stages were found for males: immature, maturing and mature, with the indication of: spermatogonia, spermatocytes, spermatids, spermatozoids and spermatophores. These data suggest the pattern described in the literature. Size at sexual maturity was 32.3 mm of carapace width for males and 31.5 mm for females. The gonadal stages observed macroscopically by volume and color were validated through histological analysis and proved to be useful method for the rapid identification of sexual maturity in the species. The present study offers previously unpublished data on the reproductive biology of Sylviocarcinus pictus.

Morphological and Morphometric Aspects of Crassostrea rhizophorae (Guilding, 1828) Oocytes in Three Stages of the Gonadal Cycle

Crassostrea rhizophorae (Guilding, 1828) es una de las especies de ostras tropicales cultivadas en la costa brasilera, que presenta alto valor comercial, no existiendo informacion sobre las caracteristicas gonadales, durante las fases reproductivas de esta especie. El objetivo de este trabajo fue analizar la morfologia de los ovocitos y de los foliculos gonadales de Crassostrea rhizophorae, en tres fases del ciclo gonadal. Analizando los cortes histologicos de las gonadas y considerando los ovocitos que presentaban nucleo y nucleolo evidentes, fueron determinadas tres fases del ciclo gonadal: gametogenesis inicial, crecimiento y maduracion. En la fase de gametogenesis inicial, el diametro de los foliculos y de los ovocitos era de 180,29 (± 41,91) e 18,66 (± 6,85) µm, respectivamente; tambien identificamos gran cantidad de tejido conjuntivo interfolicular y un numero mayor de ovocitos previtelogenicos. En la fase de crecimiento, el diametro de los foliculos y de los ovocitos era de 218,02 (± 43,19) y 25,92 (± 9,94) µm, respectivamente. Este fase fue caracterizada por una pequena cantidad de tejido conjuntivo interfolicular y predominio de ovocitos vitelogenicos. En la fase de maduracion, el diametro de los foliculos y de los ovocitos era de 298,16 (± 99,24) y 35,27 (± 6,2) µm, respectivamente, existiendo gran numero de ovocitos maduros. De esta manera, concluimos que durante la implantacion del cultivo, Crassostrea rhizophorae tolera la influencia de los factores intrinsecos y extrinsecos y no presenta alteraciones significativas en su actividad reproductiva

The stage of ovarian development affects organ expression of vitellogenin as well as the morphometry and ultrastructure of germ cells in the freshwater prawn Macrobrachium amazonicum (Heller, 1862)

The objective was to characterize vitellogenin expression in the ovary and hepatopancreas, and to describe the morphometry and ultrastructure of oocytes, in the freshwater prawn Macrobrachium amazonicum at various stages of ovarian development. Five ovarian stages were defined: (I) immature, (II) maturing, (III) mature, (IV) spawned, and (V) reorganized. Ovaries and hepatopancreas were analyzed by immunohistochemistry for vitellogenin expression. Vitellogenin expression in both ovary and hepatopancreas was predominantly widespread, beginning at Stage I, peaking at Stage III, and decreasing in Stages IV and V. Characterization of the ovary included measurement of the following germ cell types: oogonia (OG), and previtellogenic (PV), early vitellogenesis (EV), advanced vitellogenesis (AV), and mature (M) oocytes. Mean ± SD diameter of OG and EV oocytes in Stages I (14.2 ± 5.5 and 119.8 ± 15.7 μm) and II (17.9 ± 4.8 and 114.3 ± 34.6 μm), respectively, were significantly different from that in Stages IV (16.6 ± 4.7 and 107.0 ± 24.6 μm) and V (14.4 ± 4.1 and 101.0 ± 25.2 μm). Both scanning and transmission electron microscopy enabled identification of EV, AV and M oocytes based on the presence of a nucleus, and the organization and distribution of yolk in the cytoplasm. In summary, vitellogenesis occurred both in the hepatopancreas and ovary, with the ovary expressing vitellogenin starting as early as Stage I. This process promoted accumulation of yolk and growth of oocytes, thus favoring sexual maturation of females. This knowledge may be applied to improve production of farmed M. amazonicum.

ABO Blood groups in cebidae (Platyrrhini, Primates) from the Rio Jamari Region

Blood and saliva samples were collected from 84Aotus azarae boliviensis, 31Ateles paniscus chamek, 130Callicebus brunneus, 130Cebus apella, 117Pithecia irrorata irrorata, and 117Saimiri ustus. Saliva samples were investigated for human ABH antigens by the standard hemagglutination inhibition test. Two species,P. irrorata andC. brunneus showed monomorphism, presenting only the A blood group. Among the polymorphic species,A. paniscus andC. apella presented theO (30 and 3) and A (1 and 127) phenotypes, and the B (80) and AB (4) phenotypes were detected inA. azarae. S. ustus was the only species that presented all the four phenotypes. The observed distribution was as expected assuming Hardy-Weinberg equilibrium to be present in those species that could be tested. The ABH substances were titrated and a comparison among species was made. Serum samples were used to detect natural antibodies and the results showed some disagreement between serum and saliva phenotypes.

Reproductive seasonality of the detritivorous fish Cyphocharax abramoides (Kner, 1958) (Characiformes: Curimatidae) in flooded rivers of the eastern Amazon

The Lower Anapu River, Eastern Amazon, has a discrete flood pulse with narrow flooded areas due to the reduced influence of tides. In this environment, local precipitation might act as an important factor in the input of detritus, which can serve as a trigger for fish reproductive period. Therefore, this paper aims to determine the effects of local precipitation on the reproductive ecology of an abundant detritivorous fish in flooded rivers. Between May 2012 and April 2013, 886 specimens (471 females and 415 males) were captured monthly using gill nets. Individuals were measured, weighted, sexed, and the gonadal development stage was defined macroscopically and confirmed histologically. Sex ratio, length-weight relationship (LWR), condition factor (k), Gonadosomatic Index (GSI), relative frequency of maturity stages, and size at first gonadal maturity (L50) were estimated and tested in relation to rainfall periods. There was no difference between the expected sex ratio (1:1), and both males and females showed polyphasic growth. The condition factor indicated higher values at the beginning of the rainy season and lower values during the dry season for both sexes. GSI and relative frequency of mature individuals indicated a long reproduction period with gonadal investment starting within the dry season until early in the rainy season for spawning within the rains. The L50 value showed that males reach sexual maturity before females. Results indicated a reproductive pattern strongly influenced by rainfall, corroborating the importance of local precipitation for lacustrine environments.

COMPOSIÇÃO DE MICROFITOPLÂNCTON DE UM ESTUÁRIO DO RIO AMAZONAS, PARÁ, BRASIL

This work aims to describe the composition, relative abundance and frequency of occurrence of microphytoplankton in the Arienga River, determined from the analysis of ten samples collected in the rainy and dry seasons (May and September 2009 respectively), during five stations, using a plankton net with a mesh size of 20m. In the period studied, the rainfall showed an atypical behavior, compared to the average of the last ten years for the region, as pH and temperature did not undergone changes. A total of 128 species were identified, belonging to divisions: Dinophyta (0.78%), Chrysophyta (0.78%), Cyanobacterium (12.50%), Chlorophyta (26.56%), and Bacillariophyta (59.38%). Of Genres found, 17 had 100% of representativeness at in both fenods. It was possible to confirm two large groups, suggesting that the rainfall regime was the main controller factor of phytoplankton composition and spatial variation of species along the Arienga River. The phytoplankton diversity was considered characteristic of the Amazon region; therefore, it is considered that the human action did not affect the phytoplankton community of the Arienga River to date.

Morphological Aspect of the Midgut of Anopheles aquasalis (Curry, 1932) Insecta: Diptera

La seccion media del intestino de la hembra de Anopheles aquasalis presenta una estrecha region anterior o toraxica y una region posterior o abdominal constituida por el epitelio formado por una camada de celulas cuya porcion apical presenta microvilosidades y la porcion basal presenta un laberinto basal. La region toraxica revelo afinidad de tintura celular principalmente para componentes acidicos. El aspecto ultra estructural mostro celulas columnares con la presencia de la vesicula, mitocondrias, reticulo endoplasmatico y celulas secretoras. La region abdominal del intestino medio revelo un epitelio irregular con celulas con citoplasma basofilo y granulos acidofilos. Tambien se encontraron celulas secretoras y/o basales con citoplasma estrecho. La observacion ultra estructural de la region mostro celulas con nucleos, reticulo endoplasmatico y mitocondrias evidentes. Vesiculas largas y granulos pequenos fueron encontrados distribuidos por todo el citoplasma. La lamina basal que apoya el epitelio presento un aspecto irregular y las fibras musculares tienen organizacion longitudinal y circular y separan el epitelio del hemocele. Este estudio contribuira al analisis del mecanismo de interaccion entre el mosquito y el parasito en este especimen.

Oocyte growth, follicular complex formation and extracellular-matrix remodeling in ovarian maturation of the imperial zebra pleco fish Hypancistrus zebra

This contribution describes the growth of oocytes, addressing the formation of structures that compose the follicular complex, as well as the remodeling of the extracellular matrix, specifically laminin, fibronectin and type IV collagen during gonadal maturation. Thirty-seven females of the Acari zebra fish, Hypancistrus zebra were captured and the ovaries were submitted to histological processing for light and electron microscopy and immunohistochemistry techniques. Oogonia and four stages (I – IV) of oocytes were distinguished, and structures such as the postovulatory follicle and atretic oocytes (initial and advanced atresia) were observed. The follicular complex consists of the mature oocyte, zona radiata (Zr1, Zr2 and Zr3), follicular cells, basement membrane and theca. During oocyte growth, proteins of the extracellular matrix showed different intensities of staining. Based on these observations, a model of oocyte growth is proposed to define specific characteristics of the oocyte and the remodeling of the extracellular matrix in the ovary of H. zebra. This model of oocyte growth can be extended to other species of ornamental fishes. This study contributes data for induced fertilization and eventual conservation of this species.