Reproductive Biology of the Inseminating Glandulocaudine<i>Diapoma speculiferum</i>Cope (Teleostei: Characidae)

Azevedo, Marco Aurélio; Malabarba, Luiz Roberto; Fialho, Clarice Bernhardt

doi:10.1643/0045-8511(2000)000[0983:rbotig]2.0.co;2

Cited by 40 publications

(45 citation statements)

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“…Hence, the more accurate term ''internal insemination'' had been used recently instead ''internal fertilization'' (Burns et al, 2002;Mazzoldi et al, 2007;Parreira et al, 2009). This insemination strategy may also allow the temporal gap between mating and spawning (Pusey & Stewart, 1989;Azevedo et al, 2000), as suggested for A. longimanus in this study (based on sex ratio; discussion below).…”

Section: Discussionmentioning

confidence: 85%

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

et al. 2011

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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.O objetivo deste estudo foi avaliar alterações sazonais no índice gonadossomático (IGS%), fator de condição (K) e proporção sexual, a fim de determinar o período de atividade reprodutiva do bagre Auchenipterichthys longimanus (Siluriformes: Auchenipteridae), a partir da análise de exemplares coletados em igarapés da Floresta Nacional de Caxiuanã, estado do Pará, Brasil. Através de coletas bimestrais entre julho de 2008 e julho de 2009, foram capturados 589 exemplares de A. longimanus, sendo 251 machos e 338 fêmeas. Dentre os machos, 171 exemplares foram classificados como adultos e 80 foram jovens, e dentre as fêmeas, 249 eram adultas e 89 jovens. Por meio do estabelecimento de uma equação senoidal, a análise do IGS% evidenciou uma assincronia reprodutiva entre os sexos, pois os machos obtiveram maiores valores de IGS% em janeiro e as fêmeas apresentaram seu pico em março. Para os valores de IGS% de machos, a equação senoide mostrou-se significante somente para os valores brutos (P=0,001), sendo não identificada uma tendência com os valores médios do IGS% (P=0,136). Para as fêmeas, os valores de significância da equação senoide para o IGS% foram obtidos tanto para os dados brutos (P=0,012) quanto para os dados médios (P=0,026). Para o Fator de Condição, a equação senoide demonstrou variação nos valores brut...

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Section: Discussionmentioning

confidence: 85%

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

et al. 2011

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“…According to Malabarba & Weitzman (2003), the glandulocaudines would form a natural clade within Characidae with several genera previously classified into Tetragonopterinae subfamily (including Bryconamericus), sharing synapomorphies related to the dorsal fin and tooth arrangement. The low fecundity found in B. iheringii and glandulocaudine species (Azevedo, 2000;Azevedo et al, 2000) could be, therefore, a result of common ancestry independent of the presence of insemination or any other character related to parental care.…”

Section: Discussionmentioning

confidence: 99%

“…The relative fecundity, however, was similar to values observed in inseminating species. Species with low fecundity have, frequently, attributes such as parental care, insemination, internal fertilization or multiple spawning, strategies that may increase the chances of fertilization and/or survival of eggs and larvae (Vazzoler & Menezes, 1992;Azevedo, 2000;Azevedo et al, 2000). According to Malabarba & Weitzman (2003), the glandulocaudines would form a natural clade within Characidae with several genera previously classified into Tetragonopterinae subfamily (including Bryconamericus), sharing synapomorphies related to the dorsal fin and tooth arrangement.…”

Section: Discussionmentioning

confidence: 99%

Reproductive biology of Bryconamericus iheringii (Ostariophysi: Characidae) from rio Vacacaí, RS, Brazil

2004

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In this paper we describe some aspects of the reproduction and development of secondary sexual characters of Bryconamericus iheringii, based on the analysis of 194 females and 210 males collected monthly in the rio Vacacaí (30 o 21'34"S and 54 o 18'48"W), from April 2001 to March 2002. The reproductive period occurred from September to January (spring and summer in the Southern Hemisphere), as described for other characids of the same area. The absolute fecundity mean was 933.71 ± 303.10 oocytes, and the relative fecundity mean was 0.36 ± 0.08 oocytes per mg of total weight, being the species a multiple spawner. There was no correlation between the values of GSI and variation of biotic (stomach repletion and hepatosomatic indexes) and abiotic data (rainfall, day length and temperature) but we suggest that these factors can influence the reproduction of the species acting as "starters" of the beginning of gonadal maturation. Fin-ray hooks consist in a sexually dimorphic character of the species. Well developed hooks were found mainly in mature males, during the reproductive period and in the largest individuals.Neste trabalho são descritos aspectos da reprodução e do desenvolvimento de caracteres sexuais secundários em Bryconamericus iheringii. Foram analisados 194 fêmeas e 210 machos coletados mensalmente no rio Vacacaí (30 o 21'34"S e 54 o 18'48"W), de abril de 2001 a março de 2002. O período reprodutivo ocorreu de setembro a janeiro (primavera e verão no hemisfério sul), como descrito para outros caracídeos da mesma região. A fecundidade absoluta média foi de 933,71 ± 303,10 ovócitos e a fecundidade relativa média foi de 0,36 ± 0,08 ovócitos por mg de peso total, sendo a desova do tipo parcelada. Não houve correlação entre os valores de IGS e a variação dos dados bióticos (índices de repleção e hepatossomático) e abióticos (pluviosidade, fotoperíodo e temperatura) mas sugere-se que estes fatores possam influenciar na reprodução da espécie, atuando como desencadeadores do início da maturação gonadal. Ganchos nas nadadeiras ventrais e anal dos machos consistiram em caracteres de dimorfismo sexual da espécie. Ganchos bem desenvolvidos são encontrados principalmente em machos maduros, durante o período reprodutivo e nos maiores indivíduos.

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“…This suggests a strong selective pressure for insemination. In addition to increasing the probability of fertilization of the eggs, insemination may also allow the temporal and spatial separation of mating and oviposition, an advantage in environments that experience distinct rainy and dry seasons (Azevedo et al, 2000;Burns and Weitzman, 2005). The finding of spermatozoa in a B. axelrodi ovary containing only previtellogenic oocytes further supports this idea.…”

Section: Discussionmentioning

confidence: 99%

Reproductive morphology of Brittanichthys axelrodi (Teleostei: Characidae), a miniature inseminating fish from South America

Javonillo

Burns

Weitzman

2006

Journal of Morphology

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Light and electron microscopy were used to investigate the morphology of reproductive characters in a characid fish, Brittanichthys axelrodi. Spermatozoa were found in ovaries of females, thereby confirming insemination in this species. Bony hooks can be found on the fourth unbranched ray and branched rays 1-4 of the anal fin and the unique sigmoidally-curved ray of the caudal fin in mature males. Testes have three distinct regions: an anterior spermatogenic region, an aspermatogenic middle region lined with a simple squamous epithelium and used for storage of mature spermatozoa, and a posterior region of coiled chambers lined with a high simple cuboidal epithelium. The most posterior region appears to be instrumental in the formation and storage of spermatozeugmata, unencapsulated sperm packets. Thus far, this tripartite testis morphology is unique among characids. The mature spermatozoon has an elongate nucleus ( 5 lm in length). A striated rootlet originates at the anterior end of the distal centriole and continues to the anterior tip of the cell. The striated rootlet wraps around the entire ventral area of the anterior part of the nucleus and appears to continue around the anterior tip of the nucleus and down the dorsal side as electron-dense material. Several large, spherical mitochondria ( 0.6 lm in diameter) with lamellar cristae overlap the posterior end of the nucleus and continue beyond together with the cytoplasmic collar that contains the flagellum which lacks axonemal fins. Each spermatozeugma is lanceolate in shape when sectioned mid-sagitally, with the core staining positively for mucopolysaccharides. In both sexes, the gonopore opens posterior to the anus, with the urinary pore having a separate opening posterior to the gonopore. Bands of skeletal muscle were found in the area of the male gonopore. These morphological features are likely linked to the reproductive mode of insemination, a trait that is so far as known, relatively rare among teleost fishes, but is proving increasingly frequent among certain groups of characid fishes.

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Reproductive Biology of the Inseminating GlandulocaudineDiapoma speculiferumCope (Teleostei: Characidae)

Cited by 40 publications

References 8 publications

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

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

Reproductive biology of Bryconamericus iheringii (Ostariophysi: Characidae) from rio Vacacaí, RS, Brazil

Reproductive morphology of Brittanichthys axelrodi (Teleostei: Characidae), a miniature inseminating fish from South America

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