Gonadossomatic Index Research Articles

Reproductive cycle of the flying fish Hemiodus unimaculatus (Bloch, 1794) (Characiforms: Hemiodontidae) in the upstream area of the Tucurui hydroelectric plant, Pará, Brazil

AbstractThe reproductive cycle of Hemiodus unimaculatus in the upstream area of the Tucuruí reservoir in the Tocantins River was described. The animals were collected monthly for 1 year in the Tauiry Village, municipality of Itupiranga, Pará. The individuals had their biometry taken, the gonads removed and weighed to calculate the gonadossomatic index and processed for histological analysis. A total of 103 animals were collected, 87 females and 16 males (sex ratio of 5 females:1 male). The total length and weight of the animals did not vary significantly during the year, the females had an average length of 21,867 ± 1.55 cm and an average weight of 118.63 ± 23.4 g. The males had average length of 20.353 ± 1.39 cm and an average weight of 96.90 ± 20.2 g. Females and males were in developing phases during fall and winter, and Spawning Capable in spring and summer. Spawning Capable females were collected in the fall. The closed fishing season determined for the species does not fully cover its reproductive period. This associated with the imbalance of the sex ratio, and over‐fishing of the species may be leading the species population to decline upstream of the Tucuruí reservoir on the Tocantins River.

Sedentary fish as indicators of changes in the river flow rate after impoundment

The natural flood pulse of the Amazon basin has been altered progressively by the installation of hydroelectric dams, which have had a potentially adverse impact on the local fauna. Fish are sensitive to environmental changes, and one the way to assess how they respond is through the analysis of life history traits, such as growth patterns and reproduction. Here, we evaluated the life history traits of two sedentary cichlids, Geophagus argyrostictus and Geophagus altifrons, in the middle Xingu River (upstream and downstream sectors) pre- and post-impoundment including the flood and low water hydrological seasons. The mass-length relationship, condition factor (K), gonadossomatic index (GSI), breeding season, gonadal stages, and the length at 50% sexual maturity (L50) were analyzed. Data on river flow rates and the characteristics of the fish were collected during the pre- and post-impoundment periods. Post-impoundment, the discharge of the Xingu decreased in downstream sector. During the pre-impoundment period, the K of G. argyrostictus and female G. altifrons was lower in the upstream sector in both seasons, but higher in the downstream sector to G. argyrostictus. The GSI was lower in the post-impoundment period in both sectors and seasons in G. argyrostictus, whereas in the G. altifrons females, it was higher in the downstream sector in the low water season, but lower in the upstream sector in both seasons. In G. argyrostictus, spawning occurred in a single phase and was restricted to the low water season in both periods, whereas in G. altifrons, spawning was multiple. There was a reduction in the frequency of immature individuals in the upstream sector post-impoundment. The L50 was lower, principally in the upstream sector, in both species. Our results indicate that the growth patterns and reproduction of the two populations has been impacted, especially in the endemic G. argyrostictus. The construction of dams thus appears to place endemic species under a greatest risk of extirpation. These results provide important insights for the improvement of fish resource monitoring and the development of adequate management techniques.

Reproductive biology of north-eastern Atlantic sea cucumber species: a preliminary assessment

Reproductive biology of north-eastern Atlantic sea cucumber species: a preliminary assessment

Ovarian follicle development and genital tract characteristics in different birthweight gilts at 150days of age.

In the last decades, selection for improved prolificacy has resulted in higher litter sizes and has thereby increased the proportion of low birthweight (LW) piglets. It is well documented that LW piglets have lower growth performance, muscle accretion and poor carcass quality. However, little is known about the relations of birthweight with subsequent reproductive performance in gilts. This study investigated the effects of birthweight on reproductive tract and ovarian follicle development in 150-day-old gilts. Twenty eight female pigs of different birthweight ranges (high-HW: 1.8-2.2kg; low-LW: 0.8-1.2kg) from higher parity commercial sows were reared until 150days of age, and their body weights were recorded at weaning, end of nursery and end of the grower-finisher phase. The animals were killed and their reproductive tracts collected for biometrical and histomorphometrical analysis. LW gilts showed significantly lower body weights and growth rates during all phases of production compared to their HW counterparts (p<.01). Most biometrical measurements of the reproductive tract were similar between the experimental groups, except vaginal length and the gonadossomatic index (relative ovarian weight), which were affected by birthweight class (p<.05). LW females also showed fewer medium size (3-5mm; p<.01) ovarian follicles, pre-antral follicles (p<.07) and more atretic follicles per ovarian cortex area (p<.05). Therefore, besides the effects on post-natal growth performance, birthweight affects vaginal length and the follicular dynamics process, which may impair the reproductive performance of replacement gilts.

Desempenho reprodutivo de lambaris alimentados com grãos secos de destilaria

Avaliou-se a influência dos ní­­veis de grãos secos de destilaria com solúveis (DDGS) no desempenho reprodutivo de lambaris. Foram elaboradas dietas contendo 0%, 10%, 20% e 30% de DDGS. Os peixes foram estocados durante 150 dias em 16 tanques com biofiltro, sistema individual de aquecimento e recirculação de água, na densidade de 0,3 peixe L-1. Foram determinados: fator de condição corporal, í­­ndice gonadossomático, volume dos ovos, fertilidade inicial, fertilidade inicial relativa, taxa de fertilidade, í­­ndice de desova, fertilidade final, fertilidade final relativa, taxa de eclosão e de sobrevivência das larvas, dií­¢metro dos ovos e do vitelo e comprimento das larvas. Realizaram-se também histologia das gônadas das fêmeas e dos machos e avaliação do sêmen. Os dados foram submetidos í­Â análise de varií­¢ncia, regressão e teste de tendência. A adição de DDGS nas dietas afetou a fertilidade inicial nas fêmeas, o peso, o comprimento total e o padrão dos machos (P&lt;0,05). Para as outras variáveis não foram observadas diferenças (P&gt;0,05). Não foram evidenciadas diferenças entre as estruturas morfológicas dos ovários, mas os testí­­culos dos peixes alimentados com dieta de 30% de DDGS apresentaram células espermáticas em abundí­¢ncia. O DDGS pode ser usado como alternativa proteica, sem gerar prejuí­­zos ao desempenho reprodutivo.

Assessment of reproductive capacity in females of Callinectes danae Smith, 1869 (Brachyura, Portunoidea) during a period of high reproductive activity

The reproductive capacity of the swimming crab Callinectes danae Smith, 1869 was assessed based on the reproductive investment (RI) of ovigerous females and the gonadosomatic index (GI) of non-ovigerous adult females. Crabs were collected in June 2009 with a shrimp fishing boat at Ubatuba (23° 26′S 45° 02′W) São Paulo, Brazil. Overall, 191 adult females were analyzed, of which 108 were ovigerous and 83 non-ovigerous. The size of ovigerous females ranged from 54.5 to 79.8 mm carapace width (CW) and non-ovigerous females ranged from 56.0 to 80.9 mm CW. RI values did not differ among the size classes (ANOVA, p > 0.05), with an overall mean of 15.8%. The same occurred with the Gonadossomatic index for non-ovigerous females, for which the mean value was 11.7%. The regression between the dry weight of the egg mass and the dry weight of the crab (Student’s t, p = 0.25; ttab = 1.66; tcal = 0.66) indicated an isometric relationship for the variables analyzed. The simultaneous occurrence of gonadal maturation and embryonic development in ovigerous females suggests that these crabs may spawn at least twice in the same breeding season and reveals the need for evaluation of the allocation of energy in subsequent spawns.

&lt;b&gt;Body and testicular biometric parameters of the scorpion mud turtle (&lt;i&gt;Kinosternon scorpioides&lt;/i&gt;)

The reptile Kinosternon scorpioides is a freshwater chelonian, popularly known as jurara, and is found in the Baixada Maranhense, Maranhao State, Brazil. Due to the lack of scientific information on the reproductive biology of the species, current paper describes the body and testicular biometry and the gonad-somatic index (GSI) in adult specimens collected from the natural environment. Twenty male adults were collected in the rainy (n = 10) and dry (n = 10) seasons. Data were derived from the body, testis size and GSI and tests of correlation between these measures were performed. The body biometrics of free-living Kinosternon scorpioides is similar to those found in other studies for adult animals bred in captivity. The body weight was higher in animals collected in the rainy season than that in animals collected in the dry season. The testis size presents variations among animals captured during the rainy and dry season, but the gonadossomatic index did not vary between different groups of animals. Further studies were suggested related to the levels of sexual steroid hormones and behavioral studies to understand the factors related to the species´s reproductive cycle.

Aspectos Alimentares e Reprodutivos do Cascudo, Hypostomus pusarum (Starks, 1913) (Osteichthyes: Loricariidae) no Açude Marechal Dutra, Rio Grande do Norte, Brasil

O peixe cascudo, Hypostomus pusarum é de importância ecológica e econômica dos ecossistemas aquáticos da região neotropical. O presente estudo verificou os aspectos alimentares e reprodutivos dessa espécie no açude Marechal Dutra, Acari, Rio Grande do Norte. As capturas dos peixes foram realizadas durante o período de julho de 2011 a junho de 2012, com o auxílio de pecadores locais, que utilizaram redes de espera e tarrafas.

Microscopia e morfometria de componentes tubulares de testículos de coelhos suplementados com geleia real

Estudaram-se os efeitos da geleia real sobre a espermatogênese de coelhos tratados com diferentes concentrações de geleia real. Os tratamentos foram formados por três grupos: grupo-controle; grupo que recebeu 0,5mg/dia de geleia real; e grupo que recebeu 1,0mg/dia de geleia real. O estudo envolveu a morfometria testicular. Não houve diferença entre os tratamentos quanto aos pesos corporal (T1=3,20±0,19kg, T2=2,96±0,30kg e T3=3,21±0,37kg) e gonadal (T1=2,36±0,33g, T2=2,53±0,33g e T3=2,64±0,39g) e quanto aos índices gonadossomático (T1=0,15±0,02%, T2=0,17±0,03% e T3=0,16±0,02%) e tubulossomático (T1=0,06±0,01%; T2=0,07±0,01% e T3=0,06±0,01%). O diâmetro médio dos túbulos seminíferos (T1=225,95±13,27µm, T2=239,68±21,50µm e T3=231,57±15,94µm), a altura do epitélio seminífero (T1=66,05±5,37µm, T2= 73,47±9,11µm e T3=63,34±4,79µm) e o comprimento de túbulos seminíferos por testículo (T1=46,63±13,44m, T2=43,58±12,17m e T3=46,96±9,54m) e por grama de testículo (T1=19,50±2,68m, T2=17,12±3,91m e T3=17,78±1,98m) não diferiram entre tratamentos. Conclui-se que a suplementação com geleia real, nas doses utilizadas, não altera as características testiculares avaliadas.

Aspectos Reprodutivos de Pimelodella gracilis (Valenciennes, 1835) (Osteichthyes: Pimelodidae) do Açude da Ecoregião Caatinga

O presente trabalho verificou o fator de condição, índice hepatossomático e índice gonadossomático de Pimelodella gracilis (Valenciennes, 1835) (Osteichthyes: Pimelodidae), capturados no açude Marechal Dutra, RN. Para cada exemplar foram registradas medidas do comprimento total, peso corporal, peso das gônadas e do fígado. A relação peso-comprimento foi determinada para sexo agrupado. A proporção entre os sexos apresentou uma leve predominância das fêmeas. O coeficiente angular sugere que a espécie apresenta um crescimento do tipo alométrico negativo.

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 Caxiuanã National Forest, in the Brazilian state of Pará, 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.

FATOR DE CONDIÇÃO RELACIONADO A ASPECTOS REPRODUTIVOS DA PIAPARA (Leporinus obtusidens) (Characiformes: Anostomidae) COLETADAS A JUSANTE DA USINA HIDRELÉTRICA DO FUNIL, MINAS GERAIS, BRASIL

This study aimed to describe the seasonal variation of condition factor (K) correlated with gonadossomatic (GSI) and hepatossomatic index (HSI) of Leporinus obtusidens (Valenciennes, 1837), collected downstream of the Hidroelectric Power Station of Funil, state of Minas Gerais, Brazil, and to evaluate if these indices can indicate the reproductive period of this species. The animals were captured between September/2006 and August/2007 and grouped seasonally. The length and the weight of 110 individuals were measured to calculate K, the weight of the liver was determined to calculate HSI and the weight of the gonad to calculate GSI. The K of females and males grouped and of males alone were significantly lower (p<0.05) in the summer. As for the females alone, no significant variation of the K was observed throughout the year. The values of HSI were significantly greater during the spring and summer for both sexes, whereas the GSI of males and females was superior (p<0.05) in the summer. In the correlation tests, K was not related with the GSI and HSI factors; however, strong correlation between GSI and HSI was found. K is not an index of the reproductive period of Leporinus obtusidens (Valenciennes, 1837), whereas GSI and HIS can be used for indicating reproduction. KEYWORDS: fish; reproduction; reservoir.

Morformetria e desenvolvimento gonadal em (Oreochromis niloticus) suplementada com vitamina E

This study aimed to evaluate the effect of vitamin E supplementation in the morphometry and gonadal development of Nile tilapia (Oreochromis niloticus). Considering the weight of the gonad, gonadossomatic index, testes thickness and lumen percentage, significant differences were observed for the treatment with 150 mg/kg of vitamin E. There were observed significant differences for percentage of germinative epithelium to 150 mg/kg of vitamin E and for percentage of Leydig cells in treatment with 50 mg/kg of vitamin E. The percentage of blood vessels was higher in both treatments with 50 and 150 mg. The vitamin E requirement for gonadal development of tilapia is 150 mg/kg.

Processo de maturação das gônadas de pintado (Pseudoplatystoma corruscans) alimentado com dois níveis proteicos e suplementados com óleo de milho

Investigou-se o efeito da adição de C18:2n6, por meio da inclusão de óleo de milho em dietas com dois níveis de proteína bruta, sobre o processo de maturação de gametas de pintado, Pseudoplatystoma corruscans, mantidos em tanques-rede. Foram avaliados: taxa de sobrevivência, relação peso x comprimento, fator de condição (K) e índice gonadossomático (IGS). O experimento foi realizado entre março de 2004 e fevereiro de 2006, em 12 tanques-rede, distribuídos em seis viveiros-escavados de 600m² e densidade de estocagem de 20 peixes/tanque-rede. Utilizaram-se três tratamentos (T) com duas repetições/viveiro: T1 com 28% de PB; T2 com 28% de PB + 5% óleo de milho e T3 com 40% de PB. O crescimento foi ligeiramente mais alto nos peixes do T3. As taxas de sobrevivência foram acima de 77%. Pode-se inferir que as rações ofertadas não causaram alterações histomorfológicas durante o processo de maturação gonadal dessa espécie. O IGS e o K foram ligeiramente mais altos nos animais alimentados com a ração enriquecida com óleo de milho.

Testis response to low doses of cadmium in Wistar rats

Although it is well known that cadmium (Cd) causes adverse effects on male rat reproductive organs, few studies have quantified alterations caused by its low doses. Quantification of these alterations, especially in the testis, was measured using morphometry. A single dose of cadmium chloride (1 or 1.2 mg/kg BW) was injected i.p. in adult rats, killed after 7 or 56 days. The lower dose caused slight alterations as measured by morphometrical analysis. The higher dose caused significant reduction in testis and epididymis weight, gonadossomatic index and length of seminiferous tubule (ST) after 7 and 56 days. Cadmium significantly reduced the ST diameter after 56 days. Decreased volume density of ST, after 7 and 56 days, was accompanied by an increase in interstitium volume density. The damage caused by the dose of 1.2 mg/kg can be clearly observed with light microscope. After 7 days, the tubule lumens were filled with degenerated germ cells and multinucleated spermatid aggregates. Vacuolization of the seminiferous epithelium was also observed. After 56 days, increased damage resulted in vacuolated ST, consisting only of Sertoli cells. Scanning electron microscopy examination of the testis showed that, in the group cadmium treated (1.2 mg/kg) and killed after 56 days, the interstitial tissue presents a compact and fibrous appearance with absence of fenestrae. The seminiferous epithelium height diminished and the absence of spermatozoa can be noted. The results show that a very small difference of Cd dose causes a sudden increase in testicular damage, apparently overpowering this tissue's natural defences.

Estimating size at first maturity (L50) from Gonadossomatic Index (GSI) data

Correct estimates of size at first maturity (L50) are useful for fish stock management and different methods have been proposed. In this study we propose the use of a modified logistic to estimate L50, including a variable asymptote (A). We also test the use of the Gonadossomatic Index (GSI) as a flag to establish the reproductive status of each female fish. The method is demonstrated using GSI data for four Neotropical fish species: Characiformes: Astyanax fasciatus (n = 473) and Oligosarcus robustus (n = 297); Siluriformes: Loricariichthys anus (n = 427) and Trachelyopterus lucenai (n = 195). The results were stable enough to propose this method be used for other fish species with different life histories and with a relatively unconstrained sampling programs. Nevertheless, a wide scale test program is desirable to identify any possible bias in this approach.

Parâmetros morfofisiológicos testiculares de camundongos (Mus musculus) suplementados com geleia real

Avaliaram-se os efeitos da geleia real sobre os parâmetros morfofisiológicos testiculares de camundongos (Mus musculus). Utilizaram-se 57 machos Swiss, com quatro meses de idade, distribuídos aleatoriamente em seis tratamentos: T1: solução fisiológica, via intraperitoneal; T2: 0,1mg de geleia real, via intraperitoneal; T3: 0,2mg de geleia real, via intraperitoneal; T4: água destilada, via oral; T5: 0,1mg de geleia real, via oral; e T6: 0,2mg de geleia real, via oral. Após 45 dias de suplementação com geleia real, os animais sacrificados e pesados tiveram seus testículos coletados, incluídos em parafina e corados com hematoxilina/eosina. Não houve diferença entre os tratamentos quanto aos: pesos corporal e testicular, índice gonadossomático, diâmetro tubular, altura do epitélio, comprimento total dos túbulos seminíferos, comprimento tubular por grama de testículo, índices tubulossomático e leydigossomático e valores de proporção volumétrica referentes à túnica própria, epitélio seminífero, vaso sanguíneo e vaso linfático. Foi encontrada diferença entre T1 e T3 em relação aos túbulos seminíferos e ao espaço intertubular.

Patterns of oocyte development in natural habitat and captive Salminus hilarii Valenciennes, 1850 (Teleostei: Characidae)

Fecundity and oocyte development in Salminus hilarii female brood stock were analyzed with the aim of investigating the impact of migration impediment on oogenesis. Histological analyses of the ovaries were performed in adult females caught in two different environments--the Tietê River (natural) and captivity--and the gonadossomatic index, oocyte diameter and fecundity determined. Five germ cell development stages (oogonium, perinucleolar, cortical alveoli, vitellogenic, ripe) and two other structures (postovulatory follicles and atretic oocytes) were observed in females caught in the river. Captive animals lacked the ripe oocytes and postovulatory follicles and had a relatively higher number of atretic oocytes. Females in captivity are known to produce larger oocytes, and they release fewer eggs in each spawn (absolute fecundity) when compared with animals that are able to migrate. Our results suggest that the Tietê River is undergoing alterations which are being reflected in the reproductive performance of S. hilarii, mainly due to the presence of atretic oocytes in females caught in the river. The lack of postovulatory follicles and ripe oocytes in captive animals reveals that migratory impediment negatively impacts final oocyte maturation. However, the stage of maturation reached is adequate for ovulation induction with hormone manipulation.

Maturidade do ovário no cascudo &lt;em&gt;Hypostomus strigaticeps&lt;/em&gt; (Siluriformes, Loriicaridae)

This work studied the ovarian development of the armored catfish Hypostomus strigaticeps. Between July 2002 and June 2005, 332 females were collected monthly from the Corumbataí River, São Paulo State – Brazil. The ovaries were processed using routine histological techniques – paraffin inclusion and 5 μm thick sections stained in hematoxylin-eosin. Six types of oocytes were observed: Chromatin-nucleolus, Perinucleolar, Cortical-alveolus, Vitellogenic, Ripe and Atresic. Four maturity stages were created based on macroscopic and microscopic morphological observations, as well as on analysis of the gonadossomatic index (GSI): Rest, Maturation, Ripe and Spawned

Condicionantes ambientais na distribuição e no periodo reprodutivo do Orthopristis ruber (Cuvier) (Teleostei, Haemulidae) na Baía de Sepetiba, Rio de Janeiro, Brasil

Orthopristis ruber (Cuvier, 1830) é uma espécie muito comum na costa brasileira, sendo encontrada em baias, onde figura entre os mais abundantes peixes nos arrastos de fundo. Este trabalho tem por objetivo avaliar a influência das condicionantes ambientais na distribuição espaço-temporal e no período reprodutivo de O. ruber na Baía de Sepetiba, uma área costeira semi-fechada no sul do Rio de Janeiro. Foi realizado um programa de arrasto de fundo, entre outubro de 1998 e setembro de 1999, em três zonas da baía, estabelecidas de acordo com sua proximidade do mar (interna, central e externa). Amostras mensais de peixes foram tomadas em triplicatas em cada ocasião de amostragem, bem como foram medidas as variáveis ambientais de temperatura, salinidade, transparência e profundidade. Abundância relativa foi avaliada com base nas CPUEs (Captura por Unidade de Esforço) em termos de número e de biomassa, enquanto o período reprodutivo foi determinado com o índice gonadossomático. Um total de 866 indivíduos foi capturado, com o tamanho variando entre 31 e 293 mm de comprimento total e proporção sexual de 1:1. Um maior número de peixes foi registrado em janeiro/fevereiro e em maio, embora não tenha sido encontrada diferença na abundancia relativa entre as estações do ano. Espacialmente, os maiores números e biomassas foram registrados na zona externa. Correlação positiva significativa foi encontrada entre a abundancia relativa e a profundidade, salinidade e transparência, e negativa com a temperatura. O período reprodutivo, indicado pelos maiores valores de índices gonadosomático (IGS), provavelmente ocorre de junho a setembro, coincidindo com as menores temperaturas. Esta espécie parece ter distribuição limitada às zonas mais externa da baia, próxima à influência com o mar, com maiores influxos no verão, como provável efeito da das Águas Centrais do Atlântico Sul (ACAS) que comprimem as Águas Costeiras (AC) para a baía.