Reproduction in Australian elapid snakes II. Female reproductive cycles

1977 ◽  
Vol 25 (4) ◽  
pp. 655 ◽  
Author(s):  
R Shine
Keyword(s):  
Reproductive Effort ◽  
Placental Transfer ◽  
Energy Content ◽  
Late Summer ◽  
Egg Laying ◽  
Published Data ◽  
Maternal Size ◽  
Wet Weight ◽  
Reproductive Cycles ◽  
Second Clutch

Female reproductive cycles were studied in seven species of Australian elapid snakes, and the results compared with published information on snake faunas of other continents. Of the species studied, five are live-bearing (Austrelaps superbus, Hemiaspis signata, Notechis scutatus, Pseudechis porphyriacus and Unechis gouldii) and two egg-laying (Pseudonaja nuchalis and P. textilis). The live-bearing species usually produce one clutch per year, a higher reproductive frequency than has been found in most previously studied venomous snakes. All live-bearing species show similar seasonal timing of ovulation and parturition. Gestation occupies about 14 weeks. The egg-laying species ovulate at about the same time as sympatric live-bearers, but oviposit shortly thereafter and may produce a second clutch of eggs in late summer. P. porphyriacus shows true 'viviparity', including placental transfer of nutrients (ash content of oocytes increases during gestation, energy content decreases only slightly). The live (wet) weight of the oocytes increases up to fourfold during gestation in live-bearing species, but dry weights change very little. Extra-uterine transfer of oocytes is common. Infertility is rare in A. superbus and P. porphyriacus, but frequent in N. scutatus. Clutch size is correlated with maternal body size in all species. The ratio of clutch weight to body weight decreased slightly with increasing maternal size in N. scutatus and P. porphyriacus. Published data on reptilian 'reproductive effort' are reviewed.

Sexual dimorphism in size and plumage of the polyandrous Dotterel (Charadrius morinellus): sex roles and constraints on sexual selection

1988 ◽  
Vol 66 (6) ◽  
pp. 1334-1341
Author(s):  
John Atle Kålås
Keyword(s):  
Sexual Dimorphism ◽  
Wing Length ◽  
Pair Formation ◽  
Egg Laying ◽  
Published Data ◽  
Museum Specimens ◽  
Time Activity ◽  
Monogamous Species ◽  
First Clutch ◽  
Behaviour Data

Data on live birds and previously published data reveal that female Dotterel (Charadrius morinellus) were on average larger than males for all measurements. However, sexual dimorphism on the basis of size appears weaker than expected when Dotterel are compared with closely related monogamous species. Female museum specimens have less disrupted (brighter) plumage colours than males, and dimorphism in plumage is more pronounced than it is in size. A discriminant analysis based on plumage characters did not separate the sexes totally, however. Females moult earlier in the spring than males, but summer plumage is still not fully developed for all females by the first period of pair formation, suggesting that female plumage is most important in reproduction only after the first clutch is complete. No significant differences were evident in wing length and plumage colour between 1882–1917 and 1957–1982. Time–activity studies on the polyandrous Dotterel during the arrival, prelaying, and egg-laying periods showed small differences between the sexes in the amount of time devoted to agonistic and courtship behaviour. Data from prelaying periods showed no difference between the sexes as to who initiates bouts of courtship and agonistic behaviour. The behaviour of paired birds was highly synchronized. Three hypotheses on the slight sexual dimorphism in size and plumage of this polyandrous species are presented and discussed.

A quantitative study of the helminth parasites of the Newfoundland short-finned squid, Illex illecebrosus illecebrosus (LeSueur) (Cephalopoda:Decapoda)

1968 ◽  
Vol 46 (6) ◽  
pp. 1087-1093 ◽  
Author(s):  
Elizabeth L. Brown ◽  
William Threlfall
Keyword(s):  
Quantitative Study ◽  
Seasonal Variations ◽  
Standard Length ◽  
New Records ◽  
Parasite Burden ◽  
Late Summer ◽  
Eastern Coast ◽  
Published Data ◽  
Helminth Parasites ◽  
Host Animal

Ommastrephid squid of the subspecies Illex illecebrosus illecebrosus (LeSueur) were obtained during the late summer and early autumn of 1966 and 1967 from numerous areas around the eastern coast of the island of Newfoundland. Helminths of five genera were found, namely, Phyllobothrium sp. and Dinobothrium plicitum (both of which had previously been recorded from this host), Pelichnibothrium speciosum, Scolex polymorphus, and Nybelinia sp. The last three represent new records from this ommastrephid. The incidence of these parasites was tested for correlation with standard length and with sex of the host animal. Annual and seasonal variations in degree of infection were also noted. The greatest number of procercoids encountered were Dinobothrium plicitum. Degree of infection with helminths in 1966 and 1967 was similar (39%:40%) and contrary to earlier published data, infection by cestodes is not always directly correlated with mantle length. Any possible relations between sex of the squid and parasite burden are unclear.

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.

Do female dingo–dog hybrids breed like dingoes or dogs?

2017 ◽  
Vol 65 (2) ◽  
pp. 112 ◽  
Author(s):  
Marina S. Cursino ◽  
Lana Harriott ◽  
Benjamin L. Allen ◽  
Matthew Gentle ◽  
Luke K.-P. Leung
Keyword(s):  
Corpus Luteum ◽  
Urban Areas ◽  
Late Summer ◽  
Follicular Phase ◽  
Domestic Dogs ◽  
Effective Management ◽  
Histological Features ◽  
Future Studies ◽  
Breeding Seasonality ◽  
Reproductive Cycles

Hybridisation between animals that breed once (e.g. dingoes) and twice (e.g. domestic dogs) annually may produce offspring that breed either way. This question was investigated by determining the breeding seasonality of female dingo–dog hybrids in south-east Queensland, Australia, through evaluating macroscopic and histological features of 71 female reproductive tracts. All animals were sourced from urban areas where levels of hybridisation are generally high. Most animals trapped in summer were pups less than 6 months of age. A peak of uterus diameter and weight coincided with a peak of corpus luteum in winter. The follicular phase was characterised by growing follicles, ~1–3 mm wide, in late summer and autumn. Only two of the animals (1.4%) showed out-of-season reproductive cycles: one was found with corpus luteum in summer and another in autumn. Our data clearly show that hybrids have a single annual breeding season in winter, exhibiting the same breeding seasonality as dingoes. Our findings are similar to those found in the New Guinea singing dog. Future studies should be conducted to understand and exploit the mechanism and drivers of the breeding seasonality of dingo–dog hybrids to develop more effective management of their populations.

Freshwater Migration as a Determinant Factor in the Somatic Cost of Reproduction of Two Anadromous Coregonines of James Bay

1990 ◽  
Vol 47 (2) ◽  
pp. 318-334 ◽  
Author(s):  
Yvan Lambert ◽  
Julian J. Dodson
Keyword(s):  
Energy Cost ◽  
Reproductive Effort ◽  
Energy Content ◽  
Cost Of Reproduction ◽  
Energy Gain ◽  
Lake Whitefish ◽  
James Bay ◽  
Energy Increase ◽  
Species Specific ◽  
Somatic Energy

We tested the hypothesis that the species-specific costs of migration differentially affect reproductive effort and somatic cost of reproduction in sympatric anadromous populations of cisco (Coregonus artedii) and lake whitefish (C. clupeaformis) of James Bay. Reproductive effort, which includes the energy cost of migration, is higher for cisco. Female cisco allocate more energy to reproduction than its total energy gain. The energy invested by lake whitefish in reproduction is approximately equal to its seasonal energy gain. Reproduction results in large differences in the energy content of gonads, viscera, and carcass between reproductive and nonreproductive fish of the same length. Neither cisco nor lake whitefish are able to spawn two years in succession. The somatic energy increase of reproductive female cisco is 121% lower than the somatic energy increase of nonreproductive females; similar comparisons are 89% (female) and 103% (male) for lake whitefish. The energy cost of migration is largely responsible for the higher somatic cost of reproduction observed for cisco. These different somatic costs of migration are related to resource accumulation prior to migration and to differences in the aerobic cost of swimming between the two species in combination with the difficulty of the freshwater migration.

Mercury concentrations of the axial muscle tissues of some marine fishes of the continental shelf adjacent to Tasmania

1985 ◽  
Vol 36 (4) ◽  
pp. 509 ◽  
Author(s):  
JD Thomson
Keyword(s):  
Total Mercury ◽  
Marine Fishes ◽  
Management Tool ◽  
Published Data ◽  
Organic Mercury ◽  
Commercial Fish ◽  
Total Length ◽  
Muscle Tissues ◽  
Wet Weight ◽  
Health Regulations

The mercury concentrations of 35 commercial and potentially commercial fish species from Tasmanian waters were determined. Four species had mean total mercury concentrations above 0.5 mg kg-1 wet weight and in all four there were individuals with concentrations above 1.5 mg kg-1 wet weight. Two species of shark, Parascyllium ferrugineum and Cephaloscyllium laticeps (with sample sizes of 4 and 1, respectively), had total mercury concentrations above the limit of a mean of 1.0 mg kg-1 wet weight set by the Tasmanian Public Health regulations. Concentrations in the species were compared with published data. Organic mercury concentrations in different species ranged from 40 to 96% of the total mercury concentrations. In fewer than half the species were total mercury concentration and total length or weight significantly correlated, indicating that neither total length nor weight could be used as a universal management tool to control human mercury intake from fish consumption.

Energy budgets and reproductive ecologies of mayflies occupying disparate thermal environments

1989 ◽  
Vol 67 (11) ◽  
pp. 2782-2791 ◽  
Author(s):  
Michael J. Benton
Keyword(s):  
Body Size ◽  
Reproductive Effort ◽  
Energy Content ◽  
Aquatic Insect ◽  
Handling Time ◽  
Growth Efficiency ◽  
Life Cycles ◽  
Energy Budgets ◽  
Insect Larvae ◽  
Growth Ratio

Energy budgets were calculated for two populations of Ameletus occupying thermally disparate habitats. Growth, consumption, respiration, fecundity, and energy content of larvae and eggs were determined experimentally. Respiration rates increased and decreased with temperature throughout the life cycles of both species, although thermal effects became less pronounced with increased body size. Ameletus similior exhibited more uniform and consistently higher respiration values than Ameletus celer. Respiration costs were not constant over the life cycle of either species as has been reported for some other mayflies. Growth was influenced by both temperature (which affected instar duration) and body size (which affected growth ratio). Growth corresponded positively to temperature in both species, but was more uniform in A. celer. Net growth efficiency and assimilation were highest during cold periods in A. celer, but highest during warmer periods in A. similior. Consumption estimates were high even after adjustments for projected nonfeeding time, but unless food availability or handling time is limiting, the feeding rate of Ameletus relative to body mass may be higher than rates reported for other aquatic insect larvae. Several sources of error in consumption estimates existed, however. Assimilation efficiencies were low, but comparable to those for other herbivorous aquatic insects. Reproductive effort was higher in A. celer, but net reproductive effort was lower. The higher net reproductive effort by A. similior did not result in increased fecundity as expected, but in higher egg energy content. This and other factors suggest that A. similior displays more "K-selected" traits than A. celer, and indicates that greater fitness may not necessarily be synonymous with higher fecundity in all mayflies in all habitats.

scholarly journals On the quality of Svalbard reindeer pasture in the summer and autumn

Rangifer ◽  
1984 ◽  
Vol 4 (1) ◽  
pp. 16 ◽  
Author(s):  
Hans Staaland
Keyword(s):  
Fatty Acids ◽  
Food Intake ◽  
Energy Content ◽  
Late Summer ◽  
Ether Extract ◽  
High Quality ◽  
Svalbard Reindeer ◽  
Protein Fiber ◽  
Pasture Plants

<p>Late summer and autumn reindeer pasture plants from Adventdalen, Svalbard were analyzed for contents of fatty acids, energy content, protein, fibre, ether extract as well as content of macro minerals. Food intake of grazing reindeer in Adventdalen was estimated from fecal production. Large intake of high quality food seems to account for the growth and fattening of Svalbard reindeer during summer.</p><p>Om kvaliteten p&aring; reinbeite av reinbeite p&aring; Svalbard sommer og h&oslash;st.</p><p>Abstract in Norwegian / Sammendrag: Innholdet av fettsyrer, energi, protein, fiber, eterekstrakt og makromineraler ble analysert i reinbeiteplanter fra Adventdalen p&aring; Svalbard. Plantene ble samlet p&aring; ettersommeren. Forinntaket hos beitende rein i Adventdalen ble estimert ut fra fecesproduksjonen. Et stort inntak av for med h&oslash;y kvalitet synes &aring; kunne forklare vekst og fettlagring hos Svalbard-reinen om sommeren.</p><p>Huippuvuorten poronlaidunten laadusta kesalla ja syksylla.</p><p>Abstract in Finnish / Yhteenveto: Rasvahappojen, energian, fiiberin, eetteriuutteen ja makromineraalien sisaltoa analysoitiin poronlaidunkasveissa Huippuvuorten Adventtilaaksosta. Kasvit kerattiin loppukesalla. Adventtilaaksossa laiduntavien porojen rehun kulunki arvioitiin lannan maarasta. Korkealaatuisen rehun suuri kulutus nayttaa vovan selittaa Huippuvuorten porojen kasvun ja rasvakerrostuman kesalla.</p>

scholarly journals Breeding biology of Bengal eyed turtle Morenia petersi (Anderson 1879) in Bangladesh

2015 ◽  
Vol 42 (2) ◽  
pp. 169-181
Author(s):  
Md Lokman Hossain ◽  
Shorab Uddin Sarker ◽  
Noor Jahan Sarker
Keyword(s):  
Incubation Period ◽  
Clutch Size ◽  
Breeding Season ◽  
Gravid Female ◽  
Gonad Development ◽  
Egg Laying ◽  
Nesting Sites ◽  
Fallow Lands ◽  
The Mean ◽  
Second Clutch

This study was conducted to determine the breeding season, gonad development, egg laying period, clutch size and other biological aspects of Bengal Eyed Turtle, Morenia petersi of Bangladesh. The egg-laying period was found between November and February. The nesting sites were elevated fallow lands in secluded areas. The female turtle laid all the mature eggs at a time for each clutch at night. A gravid female turtle laid two clutches of eggs in each breeding season and the mean clutch size was 9.7 ± 1.5 eggs and mean weight of each egg was 8.9 ± 1.3 g. The eggs are elongated in shape and whitish in colour. The mean incubation period was 119 ± 30 days. The incubation period of first clutch was the longer than the second clutch. The hatchlings emerged out between April and May. Hatchery success was found 56.8%. The percentage of weight gain and specific growth rate (SGR) by weight of hatchlings in the first year was greater than second and third year. Present investigation was made to explore the possibility to raise turtle farming in captive condition.Bangladesh J. Zool. 42(2): 169-181, 2014

scholarly journals Marine amphipods as a new live prey for ornamental aquaculture: exploring the potential of Parhyale hawaiensis and Elasmopus pectenicrus

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10840
Author(s):  
Jorge Arturo Vargas-Abúndez ◽  
Humberto Ivan López-Vázquez ◽  
Maite Mascaró ◽  
Gemma Leticia Martínez-Moreno ◽  
Nuno Simões
Keyword(s):  
Sex Ratio ◽  
Reproductive Biology ◽  
Energy Content ◽  
Dry Weight ◽  
Fish Diet ◽  
Juvenile Growth ◽  
Total Length ◽  
Gross Energy ◽  
Wet Weight ◽  
Ornamental Species

Marine amphipods are gaining attention in aquaculture as a natural live food alternative to traditional preys such as brine shrimps (Artemia spp.). The use of Artemia is convenient for the culture of many marine species, but often problematic for some others, such as seahorses and other marine ornamental species. Unlike Artemia, marine amphipods are consumed by fish in their natural environment and show biochemical profiles that better match the nutritional requirements of marine fish, particularly of polyunsaturated fatty acids (PUFA), including eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. Despite their potentially easy culture, there are no established culture techniques and a deeper knowledge on the reproductive biology, nutritional profiles and culture methodologies is still needed to potentiate the optimization of mass production. The present study assessed, for the first time, the aquaculture potential of Parhyale hawaiensis and Elasmopus pectenicrus, two cosmopolitan marine gammarids (as per traditional schemes of classification) that naturally proliferate in the wild and in aquaculture facilities. For that purpose, aspects of the population and reproductive biology of the species were characterized and then a series of laboratory-scale experiments were conducted to determine amphipod productivity, the time needed to reach sexual maturity by hatchlings (generation time), cannibalism degree, the effects of sex ratio on fecundity and the effects of diet (shrimp diet, plant-based diet and commercial fish diet) on fecundity and juvenile growth. P. hawaiensis, unlike E. pectenicrus, was easily maintained and propagated in laboratory conditions. P. hawaiensis showed a higher total length (9.3 ± 1.3 mm), wet weight (14.4 ± 6.2 mg), dry weight (10.5 ± 4.4 mg), females/males sex ratio (2.24), fecundity (12.8 ± 5.7 embryos per female), and gross energy content (16.71 ± 0.67 kJ g-1) compared to E. pectenicrus (7.9 ± 1.2 mm total length; 8.4 ± 4.3 mg wet weight; 5.7 ± 3.2 mg dry weight; 1.34 females/males sex ratio; 6.5 ± 3.9 embryos per female; 12.86 ± 0.82 kJ g−1 gross energy content). P. hawaiensis juvenile growth showed a small, but significant, reduction by the use of a plant-based diet compared to a commercial shrimp and fish diet; however, fecundity was not affected, supporting the possible use of inexpensive diets to mass produce amphipods as live or frozen food. Possible limitations of P. hawaiensis could be their quite long generation times (50.9 ± 5.8 days) and relatively low fecundity levels (12.8 ± 5.7 embryos per female). With an observed productivity rate of 0.36 ± 0.08 juveniles per amphipod couple per day, P. hawaiensis could become a specialty feed for species that cannot easily transition to a formulated diet such as seahorses and other highly priced marine ornamental species.

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