Inferring diet, feeding behaviour and causes of mortality from prey-induced injuries in a New Zealand fur seal

New Zealand fur seals Arctocephalus forsteri are the most abundant of the 4 otariid (eared seal) species distributed across Australasia. Analyses of stomach contents, scats and regurgitates suggest a diet dominated by bony fish and squid, with cartilaginous species (e.g. sharks and rays) either absent or underrepresented because of a lack of preservable hard parts. Here we report on a subadult specimen from south-eastern Australia, which was found ashore emaciated and with numerous puncture wounds across its lips, cheeks, throat and the inside of its oral cavity. Fish spines embedded in the carcass revealed that these injuries were inflicted by chimaeras and myliobatiform rays (stingrays and relatives), which matches reports on the diet of A. forsteri from New Zealand, but not South Australia. Shaking and tearing of prey at the surface may help to avoid ingestion of the venomous spines, perhaps contributing to their absence from scats and regurgitates. Nevertheless, the number and severity of the facial stab wounds, some of which led to local necrosis, likely affected the animal's ability to feed, and may account for its death. Despite their detrimental effects, fish spine-related injuries are difficult to spot, and may be a common, albeit cryptic, type of trauma. We therefore recommend that stranded seals be systematically examined for this potentially life-threatening pathology.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:139

Enthalten in:

Diseases of aquatic organisms - 139(2020) vom: 30. Apr., Seite 81-86

Sprache:

Englisch

Beteiligte Personen:

Hocking, D P [VerfasserIn]
Marx, F G [VerfasserIn]
Parker, W M G [VerfasserIn]
Rule, J P [VerfasserIn]
Cleuren, S G C [VerfasserIn]
Mitchell, A D [VerfasserIn]
Hunter, M [VerfasserIn]
Bell, J D [VerfasserIn]
Fitzgerald, E M G [VerfasserIn]
Evans, A R [VerfasserIn]

Links:

Volltext

Themen:

Arctocephalus forsteri
Elephant fish
Injury
Journal Article
Pinniped
Prey processing
Stingray

Anmerkungen:

Date Completed 09.07.2020

Date Revised 09.07.2020

published: Electronic

Citation Status MEDLINE

doi:

10.3354/dao03473

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM309350387