The Nonannual, Nonseasonal Breeding Cycle of the Australian Sea Lion, Neophoca cinerea

1993 ◽  
Vol 74 (2) ◽  
pp. 270-274 ◽  
Author(s):  
L. V. Higgins
Keyword(s):  
Breeding Cycle ◽  
Sea Lion ◽  
Neophoca Cinerea ◽  
Australian Sea Lion

The Female Reproductive-Tract of the Australian Sea Lion, Neophoca-Cinerea (Peron, 1816) (Carnivora, Otariidae)

1991 ◽  
Vol 39 (3) ◽  
pp. 351 ◽  
Author(s):  
RA Tedman
Keyword(s):  
Reproductive Tract ◽  
Female Reproductive Tract ◽  
Breeding Cycle ◽  
Embryonic Diapause ◽  
Sea Lion ◽  
Neophoca Cinerea ◽  
Australian Sea Lion ◽  
Uterine Mucosa ◽  
Breeding Seasons ◽  
Uterine Glands

This first account of the morphology of the female reproductive tract of the Australian sea lion, Neophoca cinerea, is based on examination of 15 specimens. The morphology of the female reproductive tract is similar in most respects to that in other pinniped species; only features peculiar to the species are described. The Y-shaped, bicornuate uterus is for the most part septate, but has a common uterine canal that is relatively much longer than that in other otariids. The uterine mucosa of newborns is slightly hypertrophied and regresses considerably by 3 weeks postpartum. During the embryonic diapause the uterine mucosa has serrated luminal epithelium, coiled uterine glands, and tall luminal and glandular epithelia. The mucosa of the adult vagina decreases in thickness from 100-mu-m at about 2 weeks postpartum to 20-mu-m 14.5 weeks postpartum, indicative of the regressive phase typical of the delay period in other pinnipeds. The urethral meatus lacks urinary papillae, unlike most other pinnipeds. A relatively large clitoris is present, and an os clitoridis was collected from one old individual. A monoestrous cycle seemed to occur in four animals, but a polyoestrous cycle is suspected in at least one individual. Ovulation occurs from alternate ovaries in successive pregnancies. Corpora albicantia are retained for at least three breeding seasons and probably longer. Implantation occurs in the midsection of the uterine cornu, ipsilateral to the ovary that released the egg. The maximum period of embryonic diapause cannot be ascertained from the available data, although a delay of about 8-9 months is possible if the breeding cycle (pregnancy cycle) lasts about 18 months.

Breeding biology and movements of Australian sea-lions, Neophoca cinerea, off the west coasst of Western Australia

1992 ◽  
Vol 19 (4) ◽  
pp. 405 ◽  
Author(s):  
NJ Gales ◽  
AJ Cheal ◽  
GJ Pobar ◽  
P Williamson
Keyword(s):  
Breeding Season ◽  
Western Australia ◽  
West Coast ◽  
Metropolitan Region ◽  
Breeding Cycle ◽  
Sea Lion ◽  
The West ◽  
Breeding Sites ◽  
Sea Lions ◽  
Neophoca Cinerea

The Australian sea-lion, Neophoca cinerea, has a 17-18-month breeding cycle on islands off the west coast of Western Australia. Buller, North Fisherman and Beagle Is are the main pupping sites, with several very small colonies (n> 3) at the Abrolhos Is. The 4-5-month pupping seasons are synchronised at North Fisherman and Beagle Is, but the sea-lions from Buller I. breed one month later and those from the Abrolhos Is two months earlier. Pup production and pup mortality were highly variable between seasons over which observations were recorded: 129 pups were born at the main breeding sites in early 1988, the mortality in the first five months was 7.1%, whereas 181 pups were born in late 1989 of which 24.3% died. Pups remain in the vicinity of their natal islands for the first 4-5 months of life before leaving, perhaps on foraging trips, with their mothers. Most return to their natal island, although others haulout on islands up to 27 km away. Some male N. cinerea congregate in bachelor colonies on islands adjacent to the Perth metropolitan region during the non-breeding season and migrate up to 280 km north each breeding season. The status of the isolated, west-coast N. cinerea population is unknown. The current high level of human pressure on sea-lion terrestrial habitats and their food resources indicate a need for further monitoring of this species.

Functional-Morphology of the Alimentary-Tract of the Australian Sea-Lion, Neophoca-Cinerea

1987 ◽  
Vol 35 (3) ◽  
pp. 219 ◽  
Author(s):  
KC Richardson ◽  
NJ Gales
Keyword(s):  
Alimentary Tract ◽  
Fine Particles ◽  
Stomach Contents ◽  
Coarse Particles ◽  
Pyloric Antrum ◽  
Sea Lion ◽  
Neophoca Cinerea ◽  
Australian Sea Lion ◽  
Acting In Concert ◽  
Pyloric Canal

The form and topographic relationships of the alimentary tract of Neophoca cinerea is described based on dissection and radiography. A highly distensible oesophagus enters the dorsum of a large J-shaped stomach. The small intestine is long, circa 20 m, and the large intestine short, circa 1.2 m. Marker pellets (approximate diameter 1 or 3 mm) administered orally were generally found in faecal deposits containing, principally, coarse particles, i.e. of diameter greater than 1.2 mm. Most faecal deposits consisted of fine particles, i.e. with a diameter primarily of less than 1.2 mm. About 50% of the large markers remained in the alimentary tract for more than 6 days. A pyloric torus acting in concert with the patterns of pyloric peristalsis may prevent or restrict the passage of markers through the pyloric canal. Examination of the stomach contents from six animals showed that items of low digestibility, such as squid beaks and crayfish exoskeletons, were retained in the pyloric antrum.

Maternal strategies of the Australian sea lion (Neophoca cinerea) at Dangerous Reef, South Australia

2011 ◽  
Vol 59 (1) ◽  
pp. 54 ◽  
Author(s):  
Andrew D. Lowther ◽  
Simon D. Goldsworthy
Keyword(s):  
South Australia ◽  
Maternal Investment ◽  
Milk Lipid ◽  
Resource Exploitation ◽  
Sea Lion ◽  
Breeding Sites ◽  
Neophoca Cinerea ◽  
Australian Sea Lion ◽  
Spatial Differences ◽  
Pup Growth

Maternal strategies of otariid seals reflect the optimisation between resource exploitation and offspring provisioning driven across spatially separated foraging and nursing grounds. Intercolony variation in the expression of maternal strategies may represent temporal and spatial differences in resource availability, intraspecies competition or differences in life-history traits. The current study describes maternal strategies of the Australian sea lion at the largest breeding colony of the species (Dangerous Reef) and a comparative analysis was performed with data collected 16 years earlier at Seal Bay (Kangaroo Island). Significant differences in maternal strategies were characterised by lower milk lipid content (21.0 versus 28.9%), abbreviated periods onshore (0.93 versus 1.63 days) and slower pup growth rates (0.09–0.12 kg day–1) at Dangerous Reef. These data suggest flexibility in the expression of maternal investment between breeding sites and support the hypothesis of localised adaptation

Louse infestations of the Australian sea lion Neophoca cinerea.

2007 ◽  
Vol 29 (1) ◽  
pp. 103 ◽  
Author(s):  
R.R. McIntosh ◽  
M.D. Murray
Keyword(s):  
Sea Lion ◽  
Sea Lions ◽  
Neophoca Cinerea ◽  
Australian Sea Lion

Sea lions (Neophoca cinerea) at several South Australian islands were infested with the anopluran louse Antarctophthirus microchir.

Breeding age of a captive male Australian sea lion, Neophoca cinerea, at the Adelaide Zoo.

2007 ◽  
Vol 29 (1) ◽  
pp. 101 ◽  
Author(s):  
J.K. Ling ◽  
M. Guy
Keyword(s):  
Sea Lion ◽  
Neophoca Cinerea ◽  
Australian Sea Lion

A captive 3 year 2 month old female sea lion (Neophoca cinerea) mated with a 3 year 3-6 month old male and she gave birth 530 days later.

Delayed onset of vocal recognition in Australian sea lion pups (Neophoca cinerea)

2009 ◽  
Vol 96 (8) ◽  
pp. 901-909 ◽  
Author(s):  
Benjamin J. Pitcher ◽  
Heidi Ahonen ◽  
Robert G. Harcourt ◽  
Isabelle Charrier
Keyword(s):  
Sea Lion ◽  
Delayed Onset ◽  
Neophoca Cinerea ◽  
Australian Sea Lion ◽  
Vocal Recognition

scholarly journals Colony Location and Captivity Influence the Gut Microbial Community Composition of the Australian Sea Lion (Neophoca cinerea)

2016 ◽  
Vol 82 (12) ◽  
pp. 3440-3449 ◽  
Author(s):  
Tiffany C. Delport ◽  
Michelle L. Power ◽  
Robert G. Harcourt ◽  
Koa N. Webster ◽  
Sasha G. Tetu
Keyword(s):  
Microbial Community ◽  
Marine Mammals ◽  
Animal Health ◽  
Sea Lion ◽  
Content Type ◽  
Sea Lions ◽  
Neophoca Cinerea ◽  
Australian Sea Lion ◽  
Captive Populations ◽  
Gut Microbial Community

ABSTRACTGut microbiota play an important role in maintenance of mammalian metabolism and immune system regulation, and disturbances to this community can have adverse impacts on animal health. To better understand the composition of gut microbiota in marine mammals, fecal bacterial communities of the Australian sea lion (Neophoca cinerea), an endangered pinniped with localized distribution, were examined. A comparison of samples from individuals across 11 wild colonies in South and Western Australia and three Australian captive populations showed five dominant bacterial phyla:Firmicutes,Proteobacteria,Bacteroidetes,Actinobacteria, andFusobacteria. The phylumFirmicuteswas dominant in both wild (76.4% ± 4.73%) and captive animals (61.4% ± 10.8%), whileProteobacteriacontributed more to captive (29.3% ± 11.5%) than to wild (10.6% ± 3.43%) fecal communities. Qualitative differences were observed between fecal communities from wild and captive animals based on principal-coordinate analysis. SIMPER (similarity percentage procedure) analyses indicated that operational taxonomic units (OTU) from the bacterial familiesClostridiaceaeandRuminococcaceaewere more abundant in wild than in captive animals and contributed most to the average dissimilarity between groups (SIMPER contributions of 19.1% and 10.9%, respectively). Differences in the biological environment, the foraging site fidelity, and anthropogenic impacts may provide various opportunities for unique microbial establishment in Australian sea lions. As anthropogenic disturbances to marine mammals are likely to increase, understanding the potential for such disturbances to impact microbial community compositions and subsequently affect animal health will be beneficial for management of these vulnerable species.IMPORTANCEThe Australian sea lion is an endangered species for which there is currently little information regarding disease and microbial ecology. In this work, we present an in-depth study of the fecal microbiota of a large number of Australian sea lions from geographically diverse wild and captive populations. Colony location and captivity were found to influence the gut microbial community compositions of these animals. Our findings significantly extend the baseline knowledge of marine mammal gut microbiome composition and variability.

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