Observations on the biology of Carcharhinus cautus (Whitley), C. melanopterus (Quoy & Gaimard) and C. fitzroyensis (Whitley) from Northern Australia

1987 ◽  
Vol 38 (6) ◽  
pp. 701 ◽  
Author(s):  
JM Lyle
Keyword(s):  
Reproductive Biology ◽  
Teleost Fish ◽  
Species Range ◽  
Northern Australia ◽  
Males And Females ◽  
Breeding Seasons

The reproductive biology and diets of C. cautus, C. melanopterus and C. fitzroyensis from northern Australia are described. Males and females are usually mature at 84 and 91 cm, respectively, in C. cautus, 95 and 97 cm in C. melanopterus, and 88 and 100 cm in C. fitzroyensis. The species exhibit placental viviparity, have restricted breeding seasons, and individual females appear to breed annually. Breeding seasons for C. cautus and C. melanopterus are very similar: mating occurs between January and March, ovulation in February-March, and parturition in October-November. Individuals of C. fitzroyensis mate between May and July, ovulate between July and September, and give birth the. following February- April. Gestation periods for the three species range from 7 to 9 months. Approximate sizes at birth are 40 cm for C. cautus, 48 cm for C. melanopterus and 50 cm for C. fitzroyensis. Mean litter sizes are 2.9 (range 1-5) for C. cautus, 3.8 (range 3-4) for C. melanopterus and 3.7 (range 1-7) for C. fitzroyensis. Teleost fish are an important component of the diets, with crustaceans and molluscs (mainly cephalopods) of lesser importance. Snakes are eaten by C. melanopterus and C. cautus.

The effects of moonlight on nocturnal activity in bushy-tailed wood rats (Neotoma cinerea)

1999 ◽  
Vol 77 (3) ◽  
pp. 480-485 ◽  
Author(s):  
Michael G Topping ◽  
John S Millar ◽  
James A Goddard
Keyword(s):  
Light Level ◽  
Intermediate Level ◽  
Nocturnal Activity ◽  
Risk Of Predation ◽  
Increased Risk ◽  
Neotoma Cinerea ◽  
Two Measures ◽  
Males And Females ◽  
Rocky Outcrops ◽  
Breeding Seasons

The nocturnal activity of bushy-tailed wood rats (Neotoma cinerea) was monitored for two breeding seasons (1993 and 1994) in the Canadian Rockies. Radiotelemetry was used under three levels of moonlight to assess two measures of nocturnal activity: (i) the proportion of animals crossing rocky outcrops and entering the surrounding forest to forage, search for mates, or both, and (ii) the distance moved from the den site while in the forest. Males and females exhibited significant differences among moonlight levels, with greater activity on nights of intermediate-level moonlight and less activity on nights with bright or dark moonlight. There was no difference in the proportions of males and females active at any moonlight level. The distances moved from the den did not differ among moonlight levels for either males or females. Having traversed the rocks and entered the forest, individuals moved similar distances regardless of light level. These results suggest that wood rats respond to moonlight only when making the decision to cross rocks and enter the forest. This behaviour presumably serves to counteract the increased risk of predation on bright nights.

First report on the diet and reproductive biology of red-toothed triggerfish Odonus niger (Ruppell, 1836) from the south-eastern Arabian Sea

2021 ◽  
pp. 1-11
Author(s):  
Nitin Kanji Suyani ◽  
Mridula Rajesh ◽  
Kothanahally Mallegowda Rajesh
Keyword(s):  
Reproductive Biology ◽  
Arabian Sea ◽  
Feeding Habits ◽  
Gonadosomatic Index ◽  
Biological Information ◽  
The South ◽  
Spawning Period ◽  
South Eastern ◽  
Eastern Arabian Sea ◽  
Males And Females

Abstract The feeding habits and reproductive biology of red-toothed triggerfish Odonus niger (Ruppell, 1836) was analysed from 449 specimens collected from the Karnataka coast of the south-eastern Arabian Sea. Of the total stomachs examined, only 54 (12%) were empty and 395 contained food remains. The diet comprised crustacean remains (48.0%), zooplankton (21.4%), algae (16.5%), fish remains (6.1%) and cephalopod remains (5.3%) along with partially digested matter (2.3%) and detritus (0.4%). The species was found to be a generalist feeder and an omnivore. The overall sex ratio between males and females (1: 0.44) was significantly (P < 0.05) different. Histological examination of the ovaries indicated asynchronous ovarian development in females, with males maturing earlier than females. The gonadosomatic index (GSI) patterns of males and females, and the presence of ripe ovaries and spermatozoids suggested that April–May is the peak spawning period. The absolute and relative fecundity estimates ranged from 16,464–312,420 eggs and 251–2812 eggs g−1 respectively. Fecundity was positively correlated with total length and body weight. The biological information on diet composition and reproductive traits provided for the first time in this study can facilitate conservation, management and sustainable exploitation of this species in the study area.

Reproductive biology of the false coral snake Oxyrhopus guibei (Colubridae) from southeastern Brazil

2002 ◽  
Vol 23 (4) ◽  
pp. 495-504 ◽  
Author(s):  
Otavio Marques ◽  
Lígia Pizzatto
Keyword(s):  
Body Size ◽  
Reproductive Biology ◽  
Rainy Season ◽  
Reproductive Activity ◽  
Climatic Conditions ◽  
Southeastern Brazil ◽  
Coral Snake ◽  
Males And Females ◽  
Reproductive Cycles ◽  
Number Of Individuals

AbstractThe reproductive biology of the false coral snake, Oxyrhopus guibei, was studied through dissection of 496 specimens, combined with observations on captive individuals. Males mature with smaller body size than females, females attain much larger body size, and male-male combat is not expected. Clutch size ranged from 3 to 20, and was correlated with female length. Reproductive cycles in both males and females seem to be continuous, with vitellogenesis and spermatogenesis occurring throughout the year. Reproductive activity in both sexes decreased at the end of the rainy season possibly due to previous intense reproductive activity in more favorable climatic conditions. The smaller number of individuals collected at the end of the rainy season apparently occurs due to the decrease of reproductive activity of this snake.

scholarly journals Evidence of breeding activity of subadult Turdus thrushes in Argentina

2019 ◽  
Vol 27 (3) ◽  
pp. 149-152
Author(s):  
Exequiel Barboza ◽  
Patricia Capllonch ◽  
Fernando Diego Ortiz ◽  
Alex E. Jahn
Keyword(s):  
Population Dynamics ◽  
Life History ◽  
Bird Species ◽  
Life History Strategies ◽  
Brood Patch ◽  
Breeding Condition ◽  
Different Populations ◽  
Males And Females ◽  
Breeding Seasons ◽  
Subadult Female

AbstractLittle is known about the age at which many Neotropical bird species first attempt to breed. We evaluated the breeding condition of 515 adult and subadult males and females among four species of Turdus thrushes (T. nigriceps, T. chiguanco, T. amaurochalinus and T. rufiventris) in Tucumán, Argentina during three breeding seasons (2015 to 2018). We registered a total of 126 individuals with brood patches and cloacal protuberances, which accounted for 24.5% of thrushes in breeding condition that we sampled. Forty thrushes had a brood patch (31.7% of those in breeding condition), of which 11 were subadults (8.7%). Eighty-six thrushes (68.3%) had a swollen cloacal protuberance, 18 of which were subadults (14.3%). Only a few of the subadults in breeding condition built nests, incubated eggs or raised nestlings. Of 130 nests we found, only 3 belonged to a subadult thrush (in all cases, a subadult female with an adult social mate), one of which was successful. Further research on these patterns among various Neotropical bird species could lead to important insights into the life history strategies that characterize different populations, and how these ultimately affect their population dynamics.

Distribution, size and sex composition, reproductive biology and diet of sharks from Northern Australia

1991 ◽  
Vol 42 (2) ◽  
pp. 151 ◽  
Author(s):  
JD Stevens ◽  
KJ McLoughlin
Keyword(s):  
Sex Ratio ◽  
Reproductive Biology ◽  
Annual Cycle ◽  
Post Partum ◽  
Austral Summer ◽  
Size Composition ◽  
Maximum Size ◽  
Northern Australia ◽  
Average Size ◽  
Size At Birth

The distribution, size composition, sex ratio, reproductive biology and diet of 17 species of shark from the families Triakidae, Hemigaleidae and Carcharhinidae from northern Australia were examined. In most of these species the sex ratio of the embryos is 1 : 1, whereas in the post-partum populations there were significantly more males than females. The results indicate four broad reproductive strategies among these sharks. In most species reproduction was distinctly seasonal with individual females giving birth each Austral summer (annual cycle) after a gestation period of 9-12 months. A second group had a very similar cycle except that individual females gave birth every second year (biennial cycle). A third group had an annual cycle but breeding was continuous throughout the year, these were mostly small bottom-associated sharks. One species had a seasonal cycle but gave birth twice each year (biannual cycle) after a 6-month gestation. The average size at birth varied from 27 to 75 cm and the average litter size varied from 2 to 34. The size at birth was about 40% of the size at maturity, which in turn was about 70% of the maximum size. Diets ranged from omnivorous to highly selective. Fish was an important component of the diet in all but one species. There was evidence of partitioning of food resources among sympatric, morphologically similar, sharks.

scholarly journals Reproductive biology of the Brazilian sharpnose shark (Rhizoprionodon lalandii) from southeastern Brazil

2007 ◽  
Vol 64 (9) ◽  
pp. 1829-1835 ◽  
Author(s):  
Fabio S. Motta ◽  
Rafael C. Namora ◽  
Otto B. F. Gadig ◽  
F. M. S. Braga
Keyword(s):  
Reproductive Biology ◽  
Positive Relationship ◽  
Ovarian Follicles ◽  
Southeastern Brazil ◽  
Brazilian Coast ◽  
Marine Science ◽  
Size At Maturity ◽  
Total Length ◽  
Males And Females ◽  
Using Data

Abstract Motta, F. S., Namora, R. C., Gadig, O. B. F., and Braga, F. M. S. 2007. Reproductive biology of the Brazilian sharpnose shark (Rhizoprionodon lalandii) from southeastern Brazil. – ICES Journal of Marine Science, 64: 1829–1835. The reproductive biology of the Brazilian sharpnose shark, Rhizoprionodon lalandii, off southeastern Brazil was investigated using data from gillnet landings. The size-at-maturity for males and females was estimated to be 59 and 62 cm total length (LT), respectively. Ovarian fecundity ranged from 3 to 7 follicles (mean = 4.54), and uterine fecundity from 1 to 5 embryos (mean = 3.3). There was a slight positive relationship between female LT and the number of ovarian follicles, but uterine fecundity was not related to female LT. Embryonic growth is fast following fertilization during summer and autumn. Gestation requires 11–12 months, and peak parturition is between August and September. A comparison of size-at-maturity between animals from northeastern and southeastern Brazil suggests the existence of at least two stocks of R. lalandii along the Brazilian coast.

scholarly journals Reproductive biology and development of gill glands in the inseminating characid, Macropsobrycon uruguayanae Eigenmann, 1915 (Cheirodontinae: Compsurini)

2010 ◽  
Vol 8 (1) ◽  
pp. 87-96 ◽  
Author(s):  
Marco A. Azevedo ◽  
Luiz R. Malabarba ◽  
John R. Burns
Keyword(s):  
Reproductive Biology ◽  
Secretory Activity ◽  
Reproductive Period ◽  
Gonadal Maturation ◽  
A Value ◽  
Secondary Lamellae ◽  
Synchronous Development ◽  
Gill Filaments ◽  
Males And Females ◽  
Columnar Cells

The reproductive biology and development of the gill gland are described for Macropsobrycon uruguayanae, an inseminating characid species of the tribe Compsurini, subfamily Cheirodontinae. Between April 2001 and March 2002, 117 males and 143 females of this species were collected in the rio Ibicuí, Uruguay basin in the State of Rio Grande do Sul, Brazil. Reproductively active individuals were present during most months sampled, indicating lack of a well-defined seasonal reproductive period. Several maturing females were found to be inseminated before completing full maturation. Histological analyses demonstrated spermatozoa within the ovaries of females in different stages of gonadal maturation collected during most months. No immature females had inseminated ovaries. Standard length at first gonadal maturation was estimated to be 24 mm for both males and females. Mean absolute fecundity was 191.08 (± 48.83 SD) oocytes per female, one of the lowest among characids. Relative fecundity was 0.539 (± 0.069 SD) oocytes per mg weight of the female, a value similar to that found for the majority of species of Cheirodontinae. The presence of two cohorts of oocytes within ovaries of M. uruguayanae indicates synchronous development, with total spawning. The mean diameter of mature oocytes was 0.6711 (± 0.1252 SD) mm, smaller than that found for the majority of species of Characidae. Gill glands occurred in all mature males, as well as in males undergoing advanced maturation. In the latter case, fewer gill filaments comprised the glands. Gill glands were not observed in immature males, males undergoing the initial stages of maturation, or in any female. A given gill gland may comprise as many as 24 filaments of the lateral hemibranch of the first gill arch. Secondary lamellae within most of the gill gland are greatly reduced, with columnar cells being present between them. These columnar cells contain abundant vesicles, suggesting secretory activity. The morphology of the gill gland of M. uruguayanae resembles that found in the majority of characid species that possess this structure.

Observations on the biology of the common torpedo (Torpedo torpedo, Linnaeus, 1758) and marbled electric ray (Torpedo marmorata, Risso, 1810) from Egyptian Mediterranean waters

1994 ◽  
Vol 45 (4) ◽  
pp. 693 ◽  
Author(s):  
SH Abdel-Aziz
Keyword(s):  
Reproductive Biology ◽  
Breeding Season ◽  
Reproductive Cycle ◽  
Strong Correlation ◽  
Maximum Size ◽  
Size At Maturity ◽  
Torpedo Marmorata ◽  
Food Items ◽  
The Common ◽  
Males And Females

The reproductive biology and diets of Torpedo torpedo and T. marmorata from Egyptian Mediterranean waters are described. Males and females reached a maximum size of 39.1 and 40.8 cm total length (TL), respectively, in T. torpedo and 38.6 and 61.2 cm TL, respectively, in T. marmorata. The size at maturity of males of T. torpedo and T. marmorata is 18 and 25.5 cm TL, respectively, and of females, is 22 and 35.5 cm TL, respectively. Both species exhibit aplacental viviparity. T. torpedo has a restricted breeding season, and individual females appear to breed annually, whereas T. marmorata females appear to have a more extended reproductive cycle (probably breeding every two years). In both species, males are capable of mating every year. In T. torpedo, mating occurs between December and February, ovulation in March-April, and parturition in late August and September after five to six months of gestation. Individuals of T. marmorata mate between November and January, ovulate between December and February, and give birth the following December after 10-12 months of gestation. Mean embryos sizes are 7.3 cm TL (range 4.6-8.2 cm TL) for T. torpedo and 8.5 cm TL (range 5.8-10.1 cm TL) for T. marmorata. Observations in Egyptian Mediterranean waters show a strong correlation between ovarian and uterine fecundity and the length of the mother in both species. Fish are an important component of the diet of the two species, as, to a lesser extent, are crustaceans for T. torpedo and cephalopods for T. marmorata. Juveniles eat a wide variety of food items, whereas adults feed only on fish.

The Reproductive Biology of the Deep-Sea Asteroid Bathybiaster Vexillifer

1982 ◽  
Vol 62 (1) ◽  
pp. 57-69 ◽  
Author(s):  
P. A. Tyler ◽  
S. L. Pain ◽  
J. D. Gage
Keyword(s):  
Shallow Water ◽  
Reproductive Biology ◽  
Deep Sea ◽  
Reproductive Strategies ◽  
Ecological Niches ◽  
Physico Chemical ◽  
Males And Females ◽  
Planktotrophic Larvae ◽  
Shallow Water Species ◽  
Water Species

INTRODUCTIONThe reproductive biology of asteroids from a wide variety of ecological niches has been examined (Farmanfarmaian et al. 1958; Cognetti & Delavault, i962;Pearse, 1965; Chia, 1968; Crump, 1971; Jangoux & Vloebergh, 1973; Worley, Franz & Hendler, 1977; Barker, 1979; Shick, Taylor & Lamb, 1981). Most of the species within this class appear to show some degree of seasonal reproductive synchrony with very few species showing aseasonal reproduction (Shick et al. 1981). Although the seasonally reproducing asteroids show a wide variety of reproductive strategies, from planktotrophic larvae to direct development, they all occur in relatively shallow water and are thus subject to the seasonal fluctuations of the physico-chemical environment. Only two shallow-water species, Ctenodiscus crispatus (Shick et al. 1981) and Patiriella exigua (Lawson-Kerr & Anderson, 1978), have aseasonal reproduction in both males and females. However, the deep sea is the only major environment in the world's ocean for which we have no data for the reproductive cycle of asteroids.

scholarly journals Fruit Flies (Drosophila spp.) Collection, Handling, and Maintenance: Field to Laboratory

2021 ◽  
Author(s):  
Pragya Topal ◽  
Divita Garg ◽  
Rajendra S. Fartyal
Keyword(s):  
Developmental Biology ◽  
Reproductive Biology ◽  
Cancer Biology ◽  
Life Sciences ◽  
Model Organism ◽  
Model Organisms ◽  
Chemical Studies ◽  
Males And Females ◽  
Species Specific ◽  
Food Media

As drosophilids are versatile, low maintenance and non-harming model organisms, they can be easily used in all fields of life sciences like Genetics, Biotechnology, Cancer biology, Genomics, Reproductive biology, Developmental biology, Micro chemical studies, ecology and much more. For using such a model organism, we need to learn capturing, rearing and culturing their progeny along with basic identification and differentiation between males and females. This chapter is being emphasized on techniques of capturing these flies with different and effective techniques. Along with it, most species-specific baits are discussed to catch more yield. Culture food media, a set measurement of different ingredients is used to rear the collected sample. The reasons for using each ingredient are also discussed in this chapter. At last, this chapter highlights the basic clues to identify different species in the field and lab along with learning distinguishing characteristics of males and females easily and effectively.

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