Necrophagy of a nurse shark (Ginglymostoma cirratum) by tiger sharks (Galeocerdo cuvier)

The aim of this study is to report a scavenging event, involving the consumption of a nurse shark, Ginglymostoma cirratum, by tiger sharks, Galeocerdo cuvier, at Fernando de Noronha archipelago, Brazil. Recreational divers found and photographed a bitten nurse shark carcass, just after sighting two tiger sharks near of the site. We estimated the sharks total lengths and discussed aspects of this feeding interaction using of images of forensic analysis. A straight cut on the nurse shark caudal fin, whose total lenght was estimated as 200 cm, suggest that it was caught by illegal fishing. A skin peeling process on the nurse shark fins indicates that the tiger sharks consumed it after its death, in a scavenging event. This is the first published report of a scavenging event involving the consumption ofan elasmobranch by tiger sharks, allowing a better comprehension of tiger sharks’ alimentary biology.

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Evasive mating behaviour by female nurse sharks, Ginglymostoma cirratum (Bonnaterre, 1788), in an equatorial insular breeding ground

Neotropical Ichthyology ◽

10.1590/1982-0224-20160103 ◽

2016 ◽

Vol 14 (4) ◽

Cited By ~ 6

Author(s):

André S. Afonso ◽

◽

Carlos V. Cantareli ◽

Rafael P. Levy ◽

Leonardo B. Veras ◽

...

Keyword(s):

Mating Behaviour ◽

Management Strategies ◽

Ventral Side ◽

Human Pressure ◽

Nurse Shark ◽

Ginglymostoma Cirratum ◽

Fernando De Noronha ◽

Body Rolling ◽

Female Nurse ◽

Nurse Sharks

ABSTRACT Mating events and aggregations of vulnerable nurse sharks Ginglymostoma cirratum were recorded in the insular protected area of Fernando de Noronha (FEN), Brazil, between April and August 2015. Female sharks were observed clustering in groups of up to 14 individuals in shallow water adjacent to the shore. Several evasive mating behaviours in the presence of males were noticed, including shoreward movement, positioning ventral side up at the sea surface with emerged pectoral and pelvic fins, body rolling and caudal fin thrashing. Fresh bite marks indicative of male courtship and coupling attempts were visible in female's pectoral and caudal fins. Altogether, the observed behaviours match previous reports of non-cooperative female nurse sharks during mating opportunities. An extended mating season coupled with a persistent use of inshore habitats result in nurse sharks being particularly vulnerable to human pressure during a most sensitive stage of their life cycle. The effective conservation of nurse shark populations from the western South Atlantic may thus depend on the protection of critical habitats where this species aggregates to reproduce. Explicitly addressing environmental requirements by vulnerable species in local management strategies is indispensable to ensure that human pressure, including ecotourism development, does not collide with stipulated conservation aims.

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Movement and activity patterns of the nurse shark, Ginglymostoma cirratum, in an oceanic Marine Protected Area of the South-western Atlantic

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315416001028 ◽

2016 ◽

Vol 97 (8) ◽

pp. 1565-1572 ◽

Cited By ~ 3

Author(s):

Ricardo Clapis Garla ◽

Otto Bismarck Fazzano Gadig ◽

Domingos Garrone-Neto

Keyword(s):

Protected Area ◽

Marine Protected Area ◽

Activity Patterns ◽

Nurse Shark ◽

Protective Measures ◽

Western Atlantic ◽

Ginglymostoma Cirratum ◽

Fernando De Noronha ◽

Automated Telemetry ◽

Nurse Sharks

The movement and activity patterns of the nurse shark, Ginglymostoma cirratum, a vulnerable species off Brazil, were investigated using mark-recapture and acoustic telemetry at an oceanic insular Marine Protected Area, the Fernando de Noronha Archipelago, Brazil. A total of 93 sharks were captured and tagged, ranging from 82 to 265 cm of total length (TL). Nurse sharks were captured throughout the year, and all life-stages used the insular shelf. Fifteen sharks (16% of the total) were recaptured after periods at liberty ranging from 3.5 h to 705 days, and the distances between tag and recapture locations ranged from 0.07 to 3.5 km. Site fidelity and movements of 10 sharks ranging from 107 to 265 cm TL were investigated for 18 months with an array of automated telemetry receivers. The mean period of detection of the monitored sharks was 66 days, ranging from 13 to 119 days. One individual 158 cm TL was monitored with active tracking for 17 days, with distances between daily locations ranging from 0.84 to 3.32 km, exhibiting movements similar to those of sharks monitored by automated telemetry. Despite remaining motionless or exhibiting short range movements for several hours or days, nurse sharks can be relatively wide-ranging, and protected areas alone cannot be the only conservation measure used to protect this species, which requires a set of protective measures, including fisheries management.

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