Biology of the New Zealand carpet shark Cephaloscyllium isabellum (Scyliorhinidae)

Abstract

The carpet shark Cephaloscyllium isabellum is abundant and widespread around the New Zealand coastal shelf from the tidal zone to about 500 m. Their overall depth distribution deepens with decreasing latitude, indicating a distribution moderated by water temperature. Cephaloscyllium isabellum is a generalist benthic carnivore and scavenger that uses both ambush and active searching hunting strategies. It has a broad diet (mainly fish, crustaceans, cephalopods, gastropods, and holothurians) and an apparent ability to manipulate prey to remove the shells of gastropods and pagurids before ingesting these animals. Length at maturity is about 60 cm for male and 76 cm for female C. isabellum. They may have an egg-laying peak around summer but probably reproduce throughout the year; the egg laying process is described. Females attain a larger size (c. 92 cm) than males (c. 80 cm). Growth and mortality rates are unknown, and constitute the main knowledge gap for C. isabellum and for Cephaloscyllium species in general.

Behavioural sleep in two species of buccal pumping sharks (Heterodontus portusjacksoni and Cephaloscyllium isabellum)

“…This may be due to the fact that, in this orientation, an animal has more body‐surface‐area contact with the corners of the tank, which may have been perceived as a safer sleep site than a more exposed, central area of the aquaria (Lima, Rattenborg, Lesku, & Amlaner, 2005). Moreover, this relatively protected site might more closely resemble their natural daytime habitats, resting in caves and crevices on reefs (Awruch, Frusher, Stevens, & Barnett, 2012; Horn, 2016; Nelson & Johnson, 1970). As the Port Jackson sharks were smaller in size, this orientation did not provide them with the same level of contact with the tank corners, which may explain the difference in behavioural choices between the two species.…”

“…During periods of inactivity, these sharks facilitate gas exchange by opening their mouth and lowering their mandible to draw oxygenated seawater into the mouth under negative pressure, followed by closing their mouth and raising the buccal cavity floor to push oxygen-rich water over their gills under positive pressure (Carlson & Parsons, 2001). These are buccal pumping sharks and include the Port Jackson (Heterodontus portusjacksoni) and draughtsboard (Cephaloscyllium isabellum) sharks; both species are nocturnal and are inactive for much of the daytime (Figure 1) (Horn, 2016;Kadar, Ladds, Mourier, Day, & Brown, 2019;Powter & Gladstone, 2009;Kelly et al, 2020). The diel activity patterns of these sharks show evidence of circadian organization and light plays an integral role in regulating periods of inactivity (Kadar et al, 2019;Kelly et al, 2020).…”

Diverse Activity Rhythms in Sharks (Elasmobranchii)

“…However, only the presence of swimming was noted, with no data collected on the intensity (speed and distance traveled) of swimming. Both the Port Jackson ( Heterodontus portusjacksoni ) and draughtsboard ( Cephaloscyllium isabellum ) sharks are oviparous buccal pumping sharks; they are also demersal and rest much of the 24-h day on cave floors and trenches in reefs and continental shelves (McLaughlin and O’Gower, 1971; Frick et al, 2010; Horn, 2016). Visual observations from captive and wild animals (O’Gower, 1995; O’Gower and Nash, 1978; Powter and Gladstone, 2008, 2009), as well as historic catch records (McLaughlin and O’Gower, 1971), have highlighted the movements and migratory patterns of Port Jackson sharks.…”

Small marine reserves provide conservation benefits for coastal sharks in southern New Zealand

“…Sevengill sharks are large (>2 m) coastal sharks, consuming a variety of prey such as teleosts, batoids, sharks and marine mammals (Barnett et al, 2010). In contrast, the mesopredatory species (spiny dogfish, carpet sharks and school sharks) are smaller sharks (<2 m) which feed predominantly on small prey including crustaceans, cephalopods and fish (Hanchet, 1991; Lucifora et al, 2006; Horn, 2016). For sevengill sharks, given the high proportion of zero counts and since most encounters were with solitary sharks, a binomial GLM with a logistic link function was used to test the effect of the explanatory variables on their presence (1) or absence (0) in each deployment.…”