Year-round maturity of the chaetognath Aidanosagitta regularis in the Hauraki Gulf, New Zealand

2015 ◽  
Vol 66 (9) ◽  
pp. 852 ◽  
Author(s):  
Wesley H. Webb ◽  
Mary A. Sewell
Keyword(s):  
New Zealand ◽  
Reproductive Biology ◽  
Sexual Maturity ◽  
Embryological Study ◽  
Lunar Phase ◽  
Seasonal Factors ◽  
Reproductive Study

The reproductive biology of planktonic chaetognaths is poorly known, particularly with regard to the importance of seasonal factors such as daylength, temperature and lunar phase. We undertook semilunar plankton sampling (March 2013–March 2014) in the Hauraki Gulf, New Zealand, to survey sexual maturity of the abundant chaetognath Aidanosagitta regularis (the only chaetognath species present in sufficient numbers for reproductive study). Contrary to our expectations, breeding of A. regularis appeared unconstrained by seasonal factors, as reproductively mature individuals were available year-round. This finding has implications for embryological study of the chaetognaths.

scholarly journals Reproductive Biology of Round Sardinella (Sardinella Aurita) (Valenciennes, 1847) in Senegalese Coastal Waters

2018 ◽  
Vol 9 (1) ◽  
pp. 31
Author(s):  
Ismaïla NDIAYE ◽  
Alassane SARR ◽  
Alioune FAYE ◽  
Modou THIAW ◽  
Malick DIOUF ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Reproductive Biology ◽  
Coastal Waters ◽  
Sexual Maturity ◽  
Reproductive Parameters ◽  
Monthly Variation ◽  
Relative Fecundity ◽  
The Mean ◽  
Sardinella Aurita ◽  
Somatic Index

In this study, a total of 1068 specimens Sardinella aurita of which 553 females and 515 males were examined. The objectif of this study was to determine the reproductive parameters of Sardinella aurita. The sex ratio was significantly in favor of females (55%). The size at first sexual maturity was estimated at 18.9 cm for females and 18.0 cm for males. The monthly variation of sexual maturity stages and gonado-somatic index (GSI) allowed to locate the reproduction periods from February to June and from September to December. The mean absolute fecundity was estimated at 110.794 ± 7582 oocytes whereas relative fecundity was about 422 ± 26 oocytes per gram of female.

scholarly journals Gonadal morphology, histology and spermatogenesis of striped piggy fish, Pomadasys stridens (Forsskal, 1775) (Family: Pomadasyidae) from Karachi coast, Pakistan.

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Amtyaz Safi
Keyword(s):  
Reproductive Biology ◽  
Sexual Maturity ◽  
Fat Body ◽  
Histological Structure ◽  
Reproductive State ◽  
Female Fish ◽  
Structure Morphology ◽  
Morphological Differences ◽  
The Right ◽  
The Relationship

A study was conducted on the histological structure, morphology of gonads and spermatogenesis of testes of the striped piggy fish, Pomadasys stridens from Karachi coast of Pakistan. The reproductive biology of grunt fishes, and the Pomadasys stridens in particular, is not well understood with respect to functional morphology and histology of the gonads in relation to sexual maturity. In the course of an investigation of the genetic variability of Pomadasys stridens, differences in morphology were observed between the right and left gonad of male and female fish and the size of the fat body associated with the gonads. Histological examinations were made to determine the relationship between these morphological differences and the reproductive state of the gonads. Findings made from this paper are gonad morphology, histology, and spermatogenesis and relate them to the reproductive biology of this species.

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 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.

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.

scholarly journals Sexual maturity in rabbits defined by the physical and chemical characteristics of the semen

1978 ◽  
Vol 12 (1) ◽  
pp. 37-39 ◽  
Author(s):  
M. Macari ◽  
C. R. Machado
Keyword(s):  
New Zealand ◽  
Sexual Maturity ◽  
Chemical Characteristics ◽  
Potassium Ions ◽  
Sodium Ions ◽  
Mean Values ◽  
New Zealand White Rabbits ◽  
The Mean ◽  
Physical And Chemical ◽  
Artificial Vagina

Semen was collected weekly from New Zealand white rabbits from the 1st positive mounting test to 43 weeks of age by means of an artificial vagina. The mean values of the results obtained in the 1st and 20th collection weeks were respectively: volume (ml) 0·61 ± 0·30 and 0·70 ± 0·19; pH 7·22 ± 0·50 and 7·19 ± 0±15; concentration (sperm/mm3 x 103) 750 ± 207 and 381 ± 90; fructose (mg/l00 ml) 117 ± 58 and 203 ± 121; citric acid (mg/l00 ml) 256 ± 90 and 200 ± 97; sodium ions (mEq/l) 133 ± 31 and 163 ± 46; potassium ions (mEq/l) 40 ± 21 and 29 ± 14. On the basis of these results, New Zealand white rabbits reach sexual maturity by 6 months of age.

Reproductive biology of the pelagic stingray, Pteroplatytrygon violacea (Bonaparte, 1832), in the equatorial and south-western Atlantic Ocean

2014 ◽  
Vol 65 (11) ◽  
pp. 1035 ◽  
Author(s):  
D. P. Veras ◽  
F. H. V. Hazin ◽  
I. S. L. Branco ◽  
M. T. Tolotti ◽  
G. H. Burgess
Keyword(s):  
Sex Ratio ◽  
Atlantic Ocean ◽  
Reproductive Biology ◽  
Sexual Maturity ◽  
Pregnant Female ◽  
Longline Fishery ◽  
Western Atlantic ◽  
Pregnant Females ◽  
Size At Birth ◽  
Tuna Longline

From October 2005 to March 2010, a total of 480 pelagic stingray, Pteroplatytrygon violacea, specimens, 188 females and 292 males (0.64 female : 1 male), were taken in the equatorial and south-western Atlantic by the commercial tuna longline fishery and their reproductive biology was studied. Disc widths (DW) ranged from 28.0 to 66.0 cm for females and from 34.0 to 59.6 cm for males. Size at first sexual maturity was estimated at ~48.0 cm DW (first pregnant female) for females and ~41.0 cm DW for males. Ovarian fecundity, considering only follicles larger than 0.5 cm in diameter, ranged from 1 to 17 follicles per female, while the uterine fecundity of embryos in pregnant females in Stages 2 and 3 ranged from 1 to 5 embryos per female. The sex ratio between the embryos was almost equal (1.08 female : 1 male) and the size at birth was 19.0 cm DW.

Senecio L. (Asteraceae) in Australia: Reproductive biology of a genus found primarily in unstable environments

1985 ◽  
Vol 33 (2) ◽  
pp. 197 ◽  
Author(s):  
M.E. Lawrence
Keyword(s):  
Exotic Species ◽  
Reproductive Biology ◽  
Seed Size ◽  
Breeding System ◽  
Seedling Establishment ◽  
Sexual Maturity ◽  
First Year ◽  
Perennial Species ◽  
Habitat Stability ◽  
Dispersal Potential

The reproductive biology of 28 native and four exotic species of Senecio is described in terms of their breeding system, longevity, habitat stability, seed size and number, dispersal potential and seedling establishment. Nineteen species (15 perennial, 2 annual, 2 ephemeral) are self-incompatible, 13 are self-compatible (4 perennial, 7 annual, 2 ephemeral) and nearly all occur in unstable environments. The success of the perennial species in unstable environments perhaps reflects the fact that they all reach sexual maturity within 1 year of germination and, provided populations of self-incompatible species are large enough, they can set seed in the first year.

Sign in / Sign up

Export Citation Format

Share Document