scholarly journals Reproductive biology of Moenkhausia intermedia (Eigenmann) (Pisces, Characiformes) in Itumbiara Reservoir, Goiás, Brazil

2004 ◽  
Vol 21 (3) ◽  
pp. 519-524 ◽  
Author(s):  
Renê Eiji Souza Hojo ◽  
Gilmar Bastos Santos ◽  
Nilo Bazzoli
Keyword(s):  
Sexual Dimorphism ◽  
Reproductive Biology ◽  
Reproductive Cycle ◽  
Standard Length ◽  
Gonadosomatic Index ◽  
Maturity Stage ◽  
Female Predominance

To study the reproductive biology of Moenkhausia intermedia (Eigenmann, 1908) in Itumbiara reservoir, Paranaíba river, Goiás, Brazil, a total of 301 specimens (237 females and 64 males) were captured quaterly from January to December 1993. The gonadosomatic index of females and males were related to morphologic variations of the gonads in different reproductive cycle stages (RCS). Analysis of RCS frequency and variations in the gonadosomatic index showed that M. intermedia reproduces during the whole year with fractional spawning. The smallest standard length at advanced maturity stage was estimated as 6.6 cm for females and 6.0 cm for males. The stomach repletion and coelomic fat indexes of both sexes reached peak values in the rest stage, suggesting that this species probably store energy in this phase and consume its fat reserve during reproduction. In the Itumbiara reservoir there was female predominance (4:1). Males were smaller than females, indicating sexual dimorphism in M. intermedia.

scholarly journals Distribution and reproductive biology of the Electric ray Discopyge tschudii Heckel, 1846 in San Matías Gulf, Northern Patagonia, Argentina

2011 ◽  
Vol 9 (4) ◽  
pp. 831-838 ◽  
Author(s):  
Marilú Estalles ◽  
Nidia Marina Coller ◽  
Edgardo Ernesto Di Giácomo ◽  
María Raquel Perier
Keyword(s):  
Sexual Dimorphism ◽  
Reproductive Biology ◽  
Reproductive Cycle ◽  
Southern Chile ◽  
Southern Brazil ◽  
Southwest Atlantic ◽  
Aggregate Distribution ◽  
Northern Patagonia ◽  
Southeast Pacific ◽  
Discopyge Tschudii

The Electric ray Discopyge tschudii is distributed in the Southwest Atlantic from southern Brazil to southern Argentina and in the Southeast Pacific from Peru to southern Chile. The main threat to this species is fishing. Discopyge tschudii is noncommercial and individuals caught are discarded on board. The present study analyzes the distribution and the morphological and reproductive characteristics of this ray in San Matías Gulf (SMG), Argentina. A total of 1087 individuals were analyzed. The species presented an aggregate distribution, with the main concentrations in the northern and eastern areas of SMG, at depths below 100 m. Males ranged from 9 to 43 cm and females from 11 to 38 cm. The species presented sexual dimorphism. Males were larger and heavier than females and also matured at larger sizes. Size at 50% of maturity was estimated at 30 cm for males and 21 cm for females. A total of 199 embryos were sampled and the proportion of sexes showed no significant differences from the expected 1:1. The number of embryos per female varied from 1 to 12. The most frequent values were 2 and 5. Length at birth was estimated at 82.17 ± 3.87 mm. Based on our findings, we hypothesize that the electric ray D. tschudii completes its reproductive cycle in SMG.

scholarly journals Reproductive biology of a tetragonopterinae (osteichthyes, characidae) of the Ubatiba fluvial system, Maricá - RJ

1999 ◽  
Vol 42 (4) ◽  
Author(s):  
Rosana Mazzoni ◽  
Jaqueline Petito
Keyword(s):  
Sexual Dimorphism ◽  
Reproductive Biology ◽  
Sexual Maturity ◽  
Gonadosomatic Index ◽  
Oocyte Diameter ◽  
Fluvial System ◽  
Development Stages ◽  
Maturation Stages ◽  
Mean Size ◽  
Reproduction Period

Aspects of the reproductive biology of one Tetragonopterinae was assessed in the Ubatiba river - Maricá / RJ. Length structure and mean size suggested sexual dimorphism, females reaching larger sizes than males. The onset of sexual maturity occured at 2.8cm for both the sexes. Fecundity, determined on ripe ovaries, showed positive correlation to females size and weight and varied from 595 to 5520 for 3.9cm and 6.2cm lengths respectively. The spawning type, defined as total, was determined by the oocyte diameter frequency from ovaries in different development stages. The frequency distribution of ovarian/testis maturation stages, associated with the temporal variation of the gonadosomatic index, suggested that the reproduction period was prolonged along the whole annual cycle.

Tissue biochemical composition in relation to the reproductive cycle of deep-sea decapod Aristeus antennatus in the Portuguese south coast

2003 ◽  
Vol 83 (5) ◽  
pp. 963-970 ◽  
Author(s):  
R. Rosa ◽  
M.L. Nunes
Keyword(s):  
Fatty Acids ◽  
Reproductive Cycle ◽  
Neutral Lipids ◽  
Gonadosomatic Index ◽  
Cholesterol Content ◽  
South Coast ◽  
Hepatosomatic Index ◽  
Maturity Stage ◽  
Lipid Levels ◽  
Aristeus Antennatus

Biochemical changes during the reproductive cycle of Aristeus antennatus (Crustacea: Decapoda) on the Portuguese south coast were investigated. Proximate chemical composition, lipid classes, fatty acid profiles, glycogen and cholesterol content were determined in the muscle, ovary and hepatopancreas (HP) during a period of one year (October 2000–September 2001). Gonadosomatic index (GSI) increased significantly in June and July and during the maturation process. Hepatosomatic index (HSI) also increased throughout the ovarian maturation. A positive correlation between lipid levels in the ovary and GSI (r=0.53, P<0.05) and HSI (r=0.30, P<0.05) was found. The muscle showed very low lipid levels and higher percentages of polar lipids. Higher proportions of neutral lipids, mainly triacylglycerols, were observed in both ovary and HP. Both ovarian and HP cholesterol increased with maturation. Protein and glycogen content in the muscle, ovary and HP did not vary as a function of ovary maturity stage. From the different tissues analysed, the glycogen is mainly stored in the HP and to a lesser extent in the muscle. In both ovary and HP the major fatty acids were 16:0, 18:1(n-7), 18:1(n-9), 20:5(n-3) and 22:6(n-3), and significant increase in the levels of monounsaturated fatty acids were observed in ovary during sexual maturation, which indicates these compounds as the major sources of energy during embryonic and early larval development.

scholarly journals Reproductive Biology of Coral Catshark Atelomycterus marmoratus (Anonymous [Bennett], 1830) in Seribu Islands, Indonesia

2019 ◽  
Vol 20 (8) ◽  
Author(s):  
Selvia Oktaviyani ◽  
WANWAN KURNIAWAN ◽  
FAHMI
Keyword(s):  
Reproductive Biology ◽  
Gonadosomatic Index ◽  
Maturity Stage ◽  
Total Length ◽  
Mean Size ◽  
The Mean ◽  
First Maturity ◽  
The Relationship ◽  
Monthly Variations ◽  
Size At First Maturity

This study provides information on the reproductive biology of the coral catshark caught in the waters around Seribu Islands, Indonesia. A total of 257 coral catsharks were collected from February 2017 to January 2018. The total length of coral catshark ranged from 170 to 585 mm for females and 255-575 mm for males, respectively. The total weight of females ranged from 85 to 640 g and males from 100 to 620 g The sex ratio between females and males was 0.45 and it was not significantly different from the expected 1:1 ratio. The growth pattern of coral catsharks in Seribu Island was negatively allometric and the population was dominated by mature sharks. The mean size at first maturity was estimated to be 557 mm for females and 514 mm for males, based on to the relationship between the proportion between maturity stage and total length. The ovulation season was estimated occur from October to March, whereas September to April was mating season based on monthly variations of gonadosomatic index (GSI) values and the occurrence of egg cases in uterus.

Reproductive characteristics of the sand sole Pegusa lascaris (Soleidae), from the eastern-central Atlantic

2008 ◽  
Vol 88 (3) ◽  
pp. 629-635 ◽  
Author(s):  
José G. Pajuelo ◽  
José M. Lorenzo
Keyword(s):  
Sexual Dimorphism ◽  
Sex Ratio ◽  
Reproductive Biology ◽  
Standard Length ◽  
Spawning Season ◽  
Significant Difference ◽  
Males And Females ◽  
First Maturity ◽  
Central Atlantic ◽  
Size At First Maturity

The reproductive biology of 1318 sand sole, Pegusa lascaris, was investigated. This species is a gonochoristic species with no evidence of sexual dimorphism. The overall sex-ratio was 1 male to 0.92 females. Females predominate in the larger size intervals, with a significant difference in mean standard length and range between sexes. Size at first maturity for males and females is attained at 17.2 and 17.7 cm standard length, respectively. Vitellogenesis does not begin synchronously for all females, as a consequence the spawning season appears to be continuous. In each female spawning takes place in two batches which are spawned mainly in spring and autumn, indicating that fish are serial synchronous spawners.

scholarly journals REPRODUCTIVE BIOLOGY OF THE SPINY EEL MACROGNATHUS PANCALUS HAMILTON, 1822 FROM UPPER ASSAM, INDIA

2020 ◽  
Vol 67 (1) ◽  
Author(s):  
S.K. Abujam ◽  
S.P. Biswas
Keyword(s):  
Sexual Dimorphism ◽  
Sex Ratio ◽  
Reproductive Biology ◽  
Body Shape ◽  
Gonadosomatic Index ◽  
Percentage Distribution ◽  
Relative Fecundity ◽  
Absolute Fecundity ◽  
Maturity Stages ◽  
Fish Samples

Reproductive biology of spiny eel Macrognathus pancalus Hamilton, 1822 was studied from the waterbodies of upper Assam, India. Sexual dimorphism was easily distinguished based on their body shape and colouration. Among the 467 fish samples examined, 312 males and 155 females were identified and the Male:Female (M:F) ratio ranged from 1:0.08 in November to 1:2.17 in June with overall sex ratio of 1:0.5. Five maturity stages were identified in a year and percentage distribution of each stage was calculated. The gonadosomatic index (GSI) ranged from 0.42 to 8.08 for females and from 0.33 to 1.25 for males. The length at 50% of the fishes attained maturity (Lm50) was 9-12 cm in males and at 12-15 cm in females, indicating males matures at moderately smaller size than their female counterparts. Ova diameter ranged from 0.3 to 1.3 mm; absolute fecundity ranged from 765.48 to 1691.96 and relative fecundity from 57.9 to 152.17. M. pancalus spawned once in a year with peak spawning between June and August.

scholarly journals Population structure and reproductive biology of Loricariichthys melanocheilus Reis & Pereira, 2000 (Siluriformes: Loricariidae) in the rio Ibicuí, Brazil

2015 ◽  
Vol 13 (2) ◽  
pp. 371-382 ◽  
Author(s):  
Éverton Luís Zardo ◽  
Everton Rodolfo Behr
Keyword(s):  
Population Structure ◽  
Sex Ratio ◽  
Reproductive Biology ◽  
Condition Factor ◽  
Gonadosomatic Index ◽  
Maturity Stage ◽  
Allometric Growth ◽  
Males And Females ◽  
Lotic Environments ◽  
Gonadal Condition

The objective of this study was to analyze population structure (spatial distribution, seasonal distribution and distribution by length classes, sex ratio and length-weight relationship) and aspects of the reproductive biology of Loricariichthys melanocheilus. Fish were sampled bimonthly using gillnets and trammel nets in lentic and lotic environments in the rio Ibicuí, between the years 2000 and 2001. Were collected 410 specimens: 230 females, 164 males and 16 specimens whose sex could not be determined. A greater number of specimens were collected in October/November and December/January and in lentic environments. The greater length classes had a higher amount of females (p < 0.05) and the sex ratio in all sampling periods was 1.38 females per male. Both males and females showed positive allometric growth (b = 3.299 and b =3.487, respectively). The highest values for gonadosomatic index (GSI) and gonadal condition factor (K) were observed from August/September and peaked in October/November, just like the highest frequencies of females at maturity stage C (mature), which is indicative that the breeding season occurs at this time.

scholarly journals Reproductive biology of the Neotropical electric fish Brachyhypopomus draco (Teleostei: Hypopomidae) from southern Brazil

2009 ◽  
Vol 7 (4) ◽  
pp. 737-744 ◽  
Author(s):  
Andrea B. Schaan ◽  
Júlia Giora ◽  
Clarice B. Fialho
Keyword(s):  
Sexual Dimorphism ◽  
Sex Ratio ◽  
Reproductive Biology ◽  
Water Depth ◽  
Electric Fish ◽  
Gonadosomatic Index ◽  
Reproductive Period ◽  
Weakly Electric Fish ◽  
Hepatosomatic Index ◽  
Southern Brazil

The reproductive biology of a population of the weakly electric fish Brachyhypopomus draco from southern Brazil is described. Information is provided on the establishment of the reproductive period in this species and its relations with environmental and feeding factors, as well as on the absolute and relative fecundities, spawning type, sex ratio and sexual dimorphism. The species exhibits a relatively long reproductive period, a relative fecundity of 0.173 oocytes per mg of female total weight, and fractional spawning. The sex ratio did not differ from 1:1 during all sampled months. Sexual dimorphism related to hypertrophy of the male's distal portion of caudal filament was observed and males grew to greater lengths than females. Male gonadosomatic index (GSI) was significantly related to water depth, oxygen saturation and temperature. Female GSI was significantly related to water depth and hepatosomatic index.

Reproductive biology and sexual dimorphism of a high-altitude population of the viviparous lizard Phymaturus punae from the Andes in Argentina

2007 ◽  
Vol 28 (3) ◽  
pp. 427-432 ◽  
Author(s):  
Jorgelina Boretto ◽  
Juan Carlos Acosta ◽  
José Villavicencio ◽  
Graciela Blanco ◽  
José Marinero ◽  
...  
Keyword(s):  
Life History ◽  
Sexual Dimorphism ◽  
High Altitude ◽  
Reproductive Biology ◽  
Reproductive Cycle ◽  
Sexual Maturity ◽  
Cold Climates ◽  
Pregnant Females ◽  
Life History Data ◽  
The Andes

AbstractPhymaturus punae is a viviparous lizard endemic to the Provincial Reserve San Guillermo, San Juan (Argentina). We present the first life history data of P. punae, belonging to an interesting genus adapted to cold climates. Females reach sexual maturity at 80.6 mm, and males at 84.4 mm snout-vent length. There is sexual dimorphism represented by larger and more robust males, but females show a wider body and a proportionally greater interlimb length than males. In males, spermatozoa become abundant in both testes and epididymi in mid-summer. Vitellogenic and pregnant females occurred simultaneously in late spring and mid-summer indicating a biennial reproductive cycle.

scholarly journals Reproductive biology of pequira Bryconamericus stramineus (Eigenmann, 1908) in Funil Reservoir-MG, Brazil

2019 ◽  
Vol 79 (4) ◽  
pp. 639-645
Author(s):  
L. D. S. Murgas ◽  
M. F. Alves ◽  
W. F. Carneiro ◽  
V. O. Felizardo ◽  
R. A. Mello ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Reproductive Biology ◽  
Reproductive Cycle ◽  
Standard Length ◽  
Reproductive Stage ◽  
Oocyte Diameter ◽  
Evaluation Period ◽  
Gonadal Maturation ◽  
Mean Diameter ◽  
The Mean

Abstract In order to evaluate aspects of reproductive biology of the “pequira” ( Bryconamericus stramineus) in the elevator of the Funil Dam - MG, fish capture was carried out from November 2008 to January 2009 and 317 individuals were collected. The mean standard length (SL) of the population was 4.96 cm and mean weight 1.80 g. The females had SL of 5.0 cm, while males had a SL of 4.6 cm. A sex ratio of 2.20: 1 (females: male) was observed. Our results show that 73% of the individuals analyzed were considered adults. The species presented low fecundity, mean of 470.9 oocytes per female and a mean diameter of 221.08 μm, with an increase in oocyte diameter over the evaluation period. The length of the first gonadal maturation was estimated at 5.0 cm. The results obtained in this work suggest that the reproductive cycle of the species occurs in the analyzed period. Although this species does not have migratory reproductive habits, the presence of adults in the reproductive stage was observed in the transposition area, which suggests a search for new environments for spawning.

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