scholarly journals Reproductive biology of Sympterygia bonapartii (Chondrichthyes: Rajiformes: Arhynchobatidae) in San Matías Gulf, Patagonia, Argentina

2017 ◽  
Vol 15 (1) ◽  
Author(s):  
María L. Estalles ◽  
María R. Perier ◽  
Edgardo E. Di Giácomo
Keyword(s):  
Sexual Dimorphism ◽  
Reproductive Biology ◽  
Early Spring ◽  
Egg Laying ◽  
Reproductive Pattern ◽  
Reproductive Parameters ◽  
Egg Capsules ◽  
Northern Patagonia ◽  
Total Length

ABSTRACT This study estimates and analyses the reproductive parameters and cycle of Sympterygia bonapartii in San Matías Gulf, northern Patagonia, Argentina. A total of 827 males and 1,299 females were analysed. Males ranged from 185 to 687 mm of total length (TL) and females from 180 to 742 mm TL. Sexual dimorphism was detected; females were larger, heavier, exhibited heavier livers, wider discs and matured at lager sizes than males. Immature females ranged from 180 to 625 mm TL, maturing females from 408 to 720 mm TL, mature ones from 514 to 742 mm TL and females with egg capsules from 580 to 730 mm TL. Immature males ranged from 185 to 545 mm TL, maturing ones from 410 to 620 mm TL and mature males from 505 to 687 mm TL. Size at which 50% of the skates reached maturity was estimated to be 545 mm TL for males and 594 mm TL for females. According to the reproductive indexes analysed, S. bonapartii exhibited a seasonal reproductive pattern. Mating may occur during winter-early spring and the egg-laying season, during spring and summer.

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.

Reproductive biology of two sympatric colubrid snakes, Chironius flavolineatus and Chironius quadricarinatus, from the Brazilian Cerrado domain

2010 ◽  
Vol 31 (4) ◽  
pp. 463-473 ◽  
Author(s):  
Roberta Richard Pinto ◽  
Otavio Augusto Vuolo Marques ◽  
Ronaldo Fernandes
Keyword(s):  
Reproductive Biology ◽  
Sexual Maturity ◽  
Egg Production ◽  
Sympatric Species ◽  
Egg Laying ◽  
Reproductive Pattern ◽  
Brazilian Cerrado ◽  
Wet Season ◽  
Reproductive Cycles ◽  
First Time

AbstractThe reproductive biology of Chironius flavolineatus and C. quadricarinatus from the Brazilian Cerrado domain is described, including sexual maturity, female fecundity, and reproductive cycles of males and females. Egg-laying is recorded here for the first time for C. quadricarinatus. Males of both species attain sexual maturity with a smaller snout-vent length than females. Females of C. flavolineatus have an extended reproductive cycle with egg production during the wet season, whereas males exhibit year-round sperm production. Chironius quadricarinatus has continuous reproductive cycles in both sexes. Differences in reproductive pattern between these two sympatric species are probably related to phylogenetic constraints on intrageneric lineages of Chironius.

scholarly journals Reproductive biology and embryonic development of Centroscymnus coelolepis in Portuguese mainland waters

2003 ◽  
Vol 60 (6) ◽  
pp. 1335-1341 ◽  
Author(s):  
Ana Veríssimo ◽  
Leonel Gordo ◽  
Ivone Figueiredo
Keyword(s):  
Sex Ratio ◽  
Embryonic Development ◽  
Reproductive Biology ◽  
Sexual Maturity ◽  
Sampling Period ◽  
Yolk Sac ◽  
Pregnant Female ◽  
Reproductive Parameters ◽  
Reproductive Characteristics ◽  
Total Length

Abstract A total of 871 females (76–122 cm) and 86 males (68–100 cm) of Centroscymnus coelolepis caught in Portuguese mainland waters were examined for reproductive characteristics. One hermaphroditic individual of 95 cm was found. Males were few in numbers and dominated by immature specimens. Female length at first sexual maturity was 98.5 cm. Mean ovarian and uterine fecundity were 13.2 oocytes per female and 9.9 embryos per pregnant female, respectively. Total length of embryos with completely absorbed external yolk sacs ranged between 233 and 300 mm. Sex ratio (F/M) of embryos with completely absorbed external yolk sac was 0.9. All stages of reproduction were found during the 12-month sampling period. Results were compared with those from other regions. A hypothesis is formulated on the existence of several regional populations based on morphometric and reproductive parameters observed in different areas.

Reproduction of Heterodontus portusjacksoni in Victoria, Australia: evidence of two populations and reproductive parameters for the eastern population

2007 ◽  
Vol 58 (10) ◽  
pp. 956 ◽  
Author(s):  
Javier Tovar-Ávila ◽  
Terence I. Walker ◽  
Robert W. Day
Keyword(s):  
Population Analysis ◽  
Sampling Bias ◽  
Early Spring ◽  
Egg Laying ◽  
Late Winter ◽  
Reproductive Parameters ◽  
Breeding Populations ◽  
Eastern Australia ◽  
Western Victoria ◽  
Far Eastern

Significant differences in the length–frequency composition of catch samples, mass–length relationships and length-at-maturity found between Heterodontus portusjacksoni from western and far-eastern Victoria, suggest the presence of at least two separate breeding populations off south-eastern Australia, with some mixing between these regions. In each region females attain a larger size than males, and collectively those sharks in western Victoria are smaller, present higher mass-at-length, and lower length-at-maturity than those in far-eastern Victoria. These regional differences might be a result of sampling bias, length-selective fishing mortality, environmental conditions, or genetic differences. However, tagging evidence from previous studies and the presence of two bio-geographic provinces in the region support the hypothesis of two separate breeding populations. The essential reproductive parameters for H. portusjacksoni population analysis in far-eastern Victoria were determined, using a novel method to estimate fecundity and the ovarian cycle of an egg-laying species. In this region, females have between 6 and 20 pre-ovulatory oocytes (average = 14, n = 29, standard deviation = 3.71) before the reproductive season. The species has an annual reproductive cycle correlated with water temperature, with ovulation starting during late winter to early spring and a ~6 month egg-laying period. The period from the onset of vitellogenesis to ovulation of oocytes is ~18 months.

reproductive biology of the blackmouth catshark, galeus melastomus (chondrichthyes: scyliorhinidae) off the south coast of portugal

2005 ◽  
Vol 85 (5) ◽  
pp. 1173-1183 ◽  
Author(s):  
m.e. costa ◽  
k. erzini ◽  
t.c. borges
Keyword(s):  
Sex Ratio ◽  
Reproductive Biology ◽  
Sexual Maturity ◽  
South Coast ◽  
Sexually Dimorphic ◽  
Morphometric Measurements ◽  
Egg Capsules ◽  
Total Length ◽  
Egg Deposition ◽  
Southern Portugal

the reproductive biology of 1045 female (9.5–67 cm (total length (tl)) and 1007 male (9.4–64.3 cm tl) blackmouth catsharks, galeus melastomus, was investigated. the sharks were caught off southern portugal by bottom crustacean trawlers at depths from 209 to 754 m. the sex ratio was 1:1, and this species is sexually dimorphic with males approaching maturity at smaller size than females. sexual segregation appears to be given for the stock within the study area. sexual maturity was reached at a total length above 49 cm in males and above 56 cm in females. mating and egg-deposition take place all year round, with two reproductive peaks of activity, in winter and summer. egg capsules are, on average, 54 mm long and 21 mm wide, with a maximum of 63×25 mm encountered. morphometric measurements of claspers, testes, ovaries, and oviducal glands were suitable for determining sexual maturity of blackmouth catshark.

Aspects of the reproductive biology of the blue shark Prionace glauca (Linnaeus, 1758) in the coastal waters of Ivory Coast, West Africa

2019 ◽  
Vol 99 (06) ◽  
pp. 1435-1441 ◽  
Author(s):  
Kouassi Yves Narcisse Kouamé ◽  
Kouadio Justin Konan ◽  
Nahoua Issa Ouattara ◽  
Tidiani Koné
Keyword(s):  
Sex Ratio ◽  
Reproductive Biology ◽  
Coastal Waters ◽  
Ivory Coast ◽  
Abundant Species ◽  
Reproductive Parameters ◽  
Gulf Of Guinea ◽  
Blue Shark ◽  
Prionace Glauca ◽  
Total Length

AbstractThe blue shark Prionace glauca is the most abundant species in the artisanal driftnet fishery off the coastal waters of Ivory Coast. The reproductive parameters were investigated with the aim of providing basic information on the reproductive biology for fisheries management. A total of 424 specimens (256 males and 168 females) ranging from 170–330 cm in total length (TL) were sampled between August 2014 and November 2016. Sample for embryonic sex ratio was obtained from 18 litters of 503 individuals (255 males and 248 females). The embryonic sex ratio was not significantly different from 1:1 (χ2 = 0.10, P > 0.05, N = 503). The size at 50% maturity (L50) was 218.1 cm TL for males and 223.3 cm TL for females. The litter size based on the number of embryos varied from 6 to 62, with an average of 30 embryos. Mating started in July whereas ovulation, fertilization and uterine eggs occurred in late October–November. Smallest embryos of 3–5 cm in stretch total length (STL) appeared in uterus from November to January. The embryo size varied widely among months, and well-pigmented embryos were already present in April–May samples, although most of them occurred in August–September, suggesting a gestation period of around 11 months. The absence of neonates in catches, as well as parturition females, does not support a hypothesis that parturition takes place in the Gulf of Guinea.

scholarly journals Reproductive biology of weakly electric fish Eigenmannia trilineata López and Castello, 1966 (Teleostei, Sternopygidae)

2009 ◽  
Vol 52 (3) ◽  
pp. 617-628 ◽  
Author(s):  
Júlia Giora ◽  
Clarice Bernhardt Fialho
Keyword(s):  
Sexual Dimorphism ◽  
Reproductive Biology ◽  
Electric Fish ◽  
Abiotic Factors ◽  
Reproductive Period ◽  
Weakly Electric Fish ◽  
Southern Brazil ◽  
Water Conductivity ◽  
Total Length ◽  
Weakly Electric

This study described the reproductive biology of a population of the weakly electric fish Eigenmannia trilineata from southern Brazil, providing the information on the estimation of reproductive period, fecundity, spawning type, first maturation size, and analysis of gonadal morphology and histology of the species, relating these data to alimentary and abiotic characters. The species showed a relatively long reproductive period, a relative fecundity of 0.27 oocytes per mg of total weight and a parcelled spawning type. First maturation size estimated for the females was 80.5 mm and for the males 63.5 mm of total length. Sex ratio did not differ from 1:1 under a X²test (α= 0.01) during all the sampled months. Sexual dimorphism was related to total length, and males had larger total length than females. The abiotic factors photoperiod and water conductivity presented significant correlations with female GSI, while male GSI presented a significant correlation only with photoperiod.

Reproductive phenology of Listronotus bonariensis (Kuschel) (Coleoptera:Curculionidae) in northern New Zealand pastures

1988 ◽  
Vol 78 (4) ◽  
pp. 659-668 ◽  
Author(s):  
G. M. Barker ◽  
R. A. Prestidge ◽  
R. P. Pottinger
Keyword(s):  
New Zealand ◽  
Reproductive Biology ◽  
First Generation ◽  
Reproductive Development ◽  
Early Spring ◽  
Egg Laying ◽  
Reproductive Phenology ◽  
Reproductive Maturity ◽  
The North ◽  
Listronotus Bonariensis

AbstractThe reproductive phenology of Listronotus bonariensis (Kuschel) in the north of North Island, New Zealand, was studied by dissection of adults collected at intervals from several sites. First-generation adults exhibited reproductive development and activity, followed by gonad atrophication and death. Most second-generation adults entered directly into oligopause in the autumn. Some early emergent weevils of this generation oviposited before onset of winter and reproductive dormancy. Oligopause was not intense, and reproductive maturity was gradually attained over the winter, with resumption of egg laying in early spring. These results are discussed in relation to population reproductive biology and survival.

Deposition of egg capsule and larval development of Rapana venosa (Gastropoda: Muricidae) from the south-eastern Black Sea

2007 ◽  
Vol 87 (4) ◽  
pp. 953-957 ◽  
Author(s):  
H. Saglam ◽  
E. Duzgunes
Keyword(s):  
Black Sea ◽  
Egg Laying ◽  
Reproductive Pattern ◽  
The South ◽  
Rapana Venosa ◽  
Egg Capsules ◽  
South Eastern ◽  
Larval Production ◽  
The Mean ◽  
Veliger Larvae

Egg capsules and intracapsular embryos of Rapana venosa were studied to determine the reproductive pattern of this invader species in the south-eastern Black Sea. Egg deposition of R. venosa in the laboratory at 25°C was described. Egg laying began in mid-June, reached a peak in July and ended in late August in 1996. The total number of the egg capsules per whelk ranged between 197 and 999 (mean 575 ±41). The mean length of the egg capsules was 13.26 mm. Each capsule contained between 124 and 1090 embryos with a mean of 555 ±10. Mean larval production per rapa whelk was about 392,931 ±42,731. The mean size of eggs produced was 213.8 μm. Five different stages of intracapsular development were observed. Embryos developed without nurse eggs. Veliger larvae completed their intracapsular development and hatched in 22 days at 25°C.

scholarly journals Reproduction of the angular angel shark (Squatina guggenheim): geographic differences, reproductive cycle, and sexual dimorphism

2006 ◽  
Vol 64 (1) ◽  
pp. 131-140 ◽  
Author(s):  
Jorge H. Colonello ◽  
Luis O. Lucifora ◽  
Ana M. Massa
Keyword(s):  
Sexual Dimorphism ◽  
Reproductive Cycle ◽  
Outer Part ◽  
River Estuary ◽  
Gompertz Model ◽  
Reproductive Pattern ◽  
Adult Males ◽  
Coastal System ◽  
Total Length ◽  
Geographic Differences

Abstract Colonello, J. H., Lucifora, L. O., and Massa, A. M. 2007. Reproduction of the angular angel shark (Squatina guggenheim): geographic differences, reproductive cycle, and sexual dimorphism. – ICES Journal of Marine Science, 64: 131–140. The reproductive ecology of Squatina guggenheim from two coastal areas in South America is analysed. In both sexes, individuals from ER (El Rincón coastal system, the more southern area) attained a larger maximum total length (LT) and a heavier weight at a given length than those from LP (La Plata River estuary). Females from ER mature at a significantly larger LT than females from LP. These patterns could be explained by an advantage of larger body size at higher latitudes in providing more reserves for winter, because individuals from ER have a larger liver than those from LP. Spines in the outer part of the pectoral fins were observed only in adult males. Fecundity increased with female total length. Females have a 3-y reproductive cycle, consisting of 10–12 months of gestation and 2 y of oocyte maturation. The embryonic growth fits the Gompertz model. Birth is in November or December, as inferred from embryo size and the presence of neonates and young of the year. Densities of S. guggenheim in LP peaked in spring and summer along the Uruguayan coast, suggesting a seasonal movement perpendicular to the shore. The reproductive pattern found suggests a population with low productivity.

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