Observations on the Embryonic Development of Octopus tetricus (Mollusca : Cephalopoda)

1978 ◽  
Vol 29 (1) ◽  
pp. 19 ◽  
Author(s):  
LM Joll
Keyword(s):  
Embryonic Development ◽  
Breeding Season ◽  
Wild Population ◽  
Yolk Sac ◽  
Egg Laying ◽  
Larvae And Juveniles ◽  
In The Wild

The development of O. tetricus embryos reared in the laboratory is described. The course of embryo-genesis is similar to that of O. vulgaris but the shape of stage-time plots differs. Most embryos undergo two reversions during development but failure to reverse does not prevent continued development. Both naturally and artificially hatched embryos still have the internal yolk sac, which is not fully absorbed until 4 or 5 days after hatchnig. Records of egg-laying in the laboratory and of the presence of larvae and juveniles in the wild population indicate that O. tetricus has a prolonged breeding season.

Observations on the behaviour of the smoky mouse Pseudomys fumeus (Rodentia: Muridae).

2000 ◽  
Vol 22 (1) ◽  
pp. 35 ◽  
Author(s):  
RE Woods ◽  
FD Ford
Keyword(s):  
Social Interactions ◽  
Breeding Season ◽  
Wild Population ◽  
New South ◽  
Post Partum ◽  
Small Sample ◽  
Wild Populations ◽  
South Wales ◽  
In Captivity ◽  
In The Wild

This study examined aspects of behaviour in a captive colony of smoky mice, Pseudomys fumeus, over a two year period. Wherever possible behaviours observed in the captive population are compared to data collected in a study of a wild population in south-eastern New South Wales. This paper provides the first recorded observations of behavior in this species. Both captive and wild populations of P. fumeus display strictly nocturnal circadian activity rhythms. In the captive study, P. fumeus were found to exhibit social interactions similar to some previously studied Pseudomys species. However, in the wild, the species was found to communally nest during the breeding season, behaviour not observed in other Pseudomys from similar habitats. P. fumeus in captivity can have more than two litters in one breeding season which suggests that their reproductive parameters are more flexible than previous studies of wild populations have shown. Field data indicate that post-partum oestrus can occur in this species, and that gestation lasts for approximately 30 days, although these observations are based on a small sample.

Fecundity, pouch young survivorship and breeding season of the northern bettong (Bettongia tropica) in the wild.

2001 ◽  
Vol 23 (2) ◽  
pp. 95 ◽  
Author(s):  
K Vernes ◽  
LC Pope
Keyword(s):  
Breeding Season ◽  
Wild Population ◽  
Reproductive Potential ◽  
Limited Data ◽  
Mark Recapture ◽  
Adult Females ◽  
In The Wild ◽  
Growth Equations

Reproduction in a wild population of northern bettongs (Bettongia tropica) was studied at Davies Creek in northeastern Queensland between November 1994 and February 1997. Using mark-recapture, we recorded 88 individual pouch young (PY) during the study (34 male, 45 female, 9 unknown sex). Using captive-derived growth equations we estimated that 90 % of PY survived to permanent emergence from the pouch (PEP). Birth of a new PY coincided with PEP of the previous young 78 % of the time; 12 % of births occurred within 2 - 8 weeks of PEP while the remaining 10 % probably died before PEP. 96 % of adult females carried PY at the time of capture. B. tropica bred continuously, with no significant differences in numbers of births recorded in different months. Few young that were marked in the pouch were captured as sub-adults, and none were captured as adults. Limited data on longevity indicated that B. tropica can live to at least 5 years. Our data suggest that B. tropica has a high reproductive potential; however, the fate of PY after PEP remains poorly known; and this may represent the period of greatest bettong mortality.

From brooding to hatching: new insights from a female Octopus vulgaris in the wild

2015 ◽  
Vol 96 (6) ◽  
pp. 1341-1346 ◽  
Author(s):  
Manuel E. Garci ◽  
Jorge Hernández-Urcera ◽  
Miguel Gilcoto ◽  
Raquel Fernández-Gago ◽  
Ángel F. González ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Natural Habitat ◽  
Egg Laying ◽  
Laying Date ◽  
Octopus Vulgaris ◽  
Battery Life ◽  
Brooding Period ◽  
Data Loggers ◽  
In The Wild ◽  
Reproductive Events

A brooding Octopus vulgaris female was monitored for 128 days in her natural habitat. The main reproductive events and embryonic development in relation to the temperature inside the spawning den, which was recorded by long-battery-life mini-data loggers, are described in the wild. The den temperature ranged from 12.9 to 19.3°C. The total number of egg strings was 160, and the total number of eggs spawned ranged between 139,040 and 241,760 (mean 190,400). The brooding period, the egg laying interval and the duration of the hatching course lasted 128, 35 and 43 days, respectively. Both egg laying and hatching were intermittent processes. The time taken for embryonic development was variable (85–128 d) and depended on the laying date, temperature and position of the string in the egg cluster and the position of the egg in the egg string. The first hatching observed occurred after a progressive and gradual increase of the temperature from 14.9 to 19.3°C. The 280 min of video recordings taken by scuba divers showed that several times, this female opened and closed a small window in the obstructions of the den entrance to facilitate a way out for the hatchling batches.

Oestradiol-17β in the blood during seasonal reactivation of the diapausing blastocyst in a wild population of tammar wallabies

1982 ◽  
Vol 95 (3) ◽  
pp. 293-300 ◽  
Author(s):  
A. P. F. Flint ◽  
Marilyn B. Renfree
Keyword(s):  
Embryonic Development ◽  
Corpus Luteum ◽  
Wild Population ◽  
Post Partum ◽  
Follicular Maturation ◽  
Peripheral Plasma ◽  
Cardiac Blood ◽  
Transient Rise ◽  
In The Wild ◽  
The Mean

Oestradiol-17β was measured by radioimmunoassay in cardiac blood from 143 pregnant and post-partum tammar wallabies shot in the wild during reactivation of the diapausing blastocyst, embryonic development, birth and post-partum oestrus. A transient rise in circulating oestradiol on 3 January coincided with or shortly preceded corpus luteum growth and blastocyst expansion; before 5 January mean corpus luteum weight was 14·3± 0·44 mg (n = 65), while thereafter it exceeded 20 mg in two-thirds of the animals. Expanded blastocysts were first noted on 5 January. A second rise in the concentration of oestradiol in plasma, which occurred in late January, preceded parturition and coincided with follicular maturation; the mean (± s.e.m.) oestradiol concentration before 17 January was 27·9 ±1·10 pmol/l (n = 110), whereas on or after this date it was 57·3 ± 4·15 pmol/l (n = 33). Thus oestradiol levels in peripheral plasma increased at parturition and post-partum oestrus, and showed a rise early in gestation which may be related to the termination of diapause.

scholarly journals Internal embryonic development in a non-copulatory, egg-laying teleost, the three-spined stickleback, Gasterosteus aculeatus

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Laura L. Dean ◽  
Shaun Robertson ◽  
Muayad Mahmud ◽  
Andrew D. C. MacColl
Keyword(s):  
Embryonic Development ◽  
Gasterosteus Aculeatus ◽  
Egg Laying

scholarly journals A Genome Scan for Quantitative Trait Loci in a Wild Population of Red Deer (Cervus elaphus)

Genetics ◽  
2002 ◽  
Vol 162 (4) ◽  
pp. 1863-1873 ◽  
Author(s):  
J Slate ◽  
P M Visscher ◽  
S MacGregor ◽  
D Stevens ◽  
M L Tate ◽  
...  
Keyword(s):  
Quantitative Trait Loci ◽  
Cervus Elaphus ◽  
Quantitative Trait ◽  
Red Deer ◽  
Wild Population ◽  
Additive Genetic Variance ◽  
Model Organisms ◽  
A Genome ◽  
Trait Loci ◽  
In The Wild

Abstract Recent empirical evidence indicates that although fitness and fitness components tend to have low heritability in natural populations, they may nonetheless have relatively large components of additive genetic variance. The molecular basis of additive genetic variation has been investigated in model organisms but never in the wild. In this article we describe an attempt to map quantitative trait loci (QTL) for birth weight (a trait positively associated with overall fitness) in an unmanipulated, wild population of red deer (Cervus elaphus). Two approaches were used: interval mapping by linear regression within half-sib families and a variance components analysis of a six-generation pedigree of >350 animals. Evidence for segregating QTL was found on three linkage groups, one of which was significant at the genome-wide suggestive linkage threshold. To our knowledge this is the first time that a QTL for any trait has been mapped in a wild mammal population. It is hoped that this study will stimulate further investigations of the genetic architecture of fitness traits in the wild.

The effect of melatonin treatment during the seasonal anoestrus on the superovulatory response and embryo production of high-prolificacy Rasa Aragonesa ewes before culling

2003 ◽  
Vol 2003 ◽  
pp. 82-82
Author(s):  
F. Forcada ◽  
J.A. Abecia ◽  
J.A. Valares
Keyword(s):  
Embryonic Development ◽  
Breeding Season ◽  
Litter Size ◽  
Direct Effect ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
Melatonin Treatment ◽  
Embryo Production ◽  
Spring Equinox

The efficacy of melatonin implants inserted around the spring equinox to improve fertility and ovulation rate or litter size in Mediterranean ewes has been previously reported (Chemineau et al., 1996; Forcada et al., 2002a.), indicating the ability of the hormone to regulate the hypothalamic activity (Viguié et al., 1995). Moreover, a direct effect of melatonin on corpora lutea and embryonic development has been also reported (Wallace et al., 1988; Abecia et al., 2002). The use of prolific Rasa Aragonesa (RA) ewes (a Mediterranean breed) before culling as embryo donors has been previously tested in the breeding season (Forcada et al., 2002b.). The aim of this experiment was to improve embryo production during the seasonal anoestrus period in selected superovulated RA ewes at the end of their reproductive lives through the use of melatonin.

scholarly journals Individual tracking reveals first breeding of Oriental Storks at age 2 years in the wild

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Anton Sasin ◽  
Anna Serdyuk ◽  
Baoguang Zhu ◽  
Qingshan Zhao
Keyword(s):  
River Basin ◽  
Wild Population ◽  
Sex Identification ◽  
Amur River Basin ◽  
Amur River ◽  
Field Verification ◽  
Successful Reproduction ◽  
In The Wild ◽  
Individual Tracking

AbstractIn this study, we report the first ever documented instances of attempted and successful reproduction (rearing two offspring) of Oriental Storks (Ciconia boyciana) at age 2 years in a wild population in the middle Heilongjiang-Amur River Basin in Russia, using a combination of GPS-GSM tracking, DNA sex identification and field verification.

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