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Preparing the perfect cuttlefish meal: complex prey handling by dolphins.

Finn J, Tregenza T, Norman M - PLoS ONE (2009)

Bottom Line: The deceased cuttlefish was then returned to the seafloor, inverted and forced along the sand substrate in order to strip the thin dorsal layer of skin off the mantle, thus releasing the buoyant calcareous cuttlebone.This stepped behavioural sequence significantly improves prey quality through 1) removal of the ink (with constituent melanin and tyrosine), and 2) the calcareous cuttlebone.Aspects of the unique mass spawning aggregations of giant cuttlefish in this region of South Australia may have contributed to the evolution of this behaviour through both high abundances of spawning and weakened post-spawning cuttlefish in a small area (>10,000 animals on several kilometres of narrow rocky reef), as well as potential long-term and regular visitation by dolphin pods to this site.

View Article: PubMed Central - PubMed

Affiliation: Sciences, Museum Victoria, Melbourne, Victoria, Australia. jfinn@museum.vic.gov.au

ABSTRACT
Dolphins are well known for their complex social and foraging behaviours. Direct underwater observations of wild dolphin feeding behaviour however are rare. At mass spawning aggregations of giant cuttlefish (Sepia apama) in the Upper Spencer Gulf in South Australia, a wild female Indo-Pacific bottlenose dolphin (Tursiops aduncus) was observed and recorded repeatedly catching, killing and preparing cuttlefish for consumption using a specific and ordered sequence of behaviours. Cuttlefish were herded to a sand substrate, pinned to the seafloor, killed by downward thrust, raised mid-water and beaten by the dolphin with its snout until the ink was released and drained. The deceased cuttlefish was then returned to the seafloor, inverted and forced along the sand substrate in order to strip the thin dorsal layer of skin off the mantle, thus releasing the buoyant calcareous cuttlebone. This stepped behavioural sequence significantly improves prey quality through 1) removal of the ink (with constituent melanin and tyrosine), and 2) the calcareous cuttlebone. Observations of foraging dolphin pods from above-water at this site (including the surfacing of intact clean cuttlebones) suggest that some or all of this prey handling sequence may be used widely by dolphins in the region. Aspects of the unique mass spawning aggregations of giant cuttlefish in this region of South Australia may have contributed to the evolution of this behaviour through both high abundances of spawning and weakened post-spawning cuttlefish in a small area (>10,000 animals on several kilometres of narrow rocky reef), as well as potential long-term and regular visitation by dolphin pods to this site.

Show MeSH
Prey handling of giant cuttlefish (Sepia apama) by Indo-Pacific bottlenose dolphin (Tursiops aduncus).Prey: (a) pinned to substrate and killed; (b) lifted towards surface; (c) beaten with snout to release ink; (d) consumed whole.
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pone-0004217-g002: Prey handling of giant cuttlefish (Sepia apama) by Indo-Pacific bottlenose dolphin (Tursiops aduncus).Prey: (a) pinned to substrate and killed; (b) lifted towards surface; (c) beaten with snout to release ink; (d) consumed whole.

Mentions: Pinned thrust kill: A rapid downward vertical thrust was effected by the dolphin using a powerful tail beat (Fig. 1b, 2a), accompanied by a whole body twist that broke the cuttlebone and/or cephalic cartilage (with a loud click audible to divers), instantly killing the cuttlefish.


Preparing the perfect cuttlefish meal: complex prey handling by dolphins.

Finn J, Tregenza T, Norman M - PLoS ONE (2009)

Prey handling of giant cuttlefish (Sepia apama) by Indo-Pacific bottlenose dolphin (Tursiops aduncus).Prey: (a) pinned to substrate and killed; (b) lifted towards surface; (c) beaten with snout to release ink; (d) consumed whole.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2626284&req=5

pone-0004217-g002: Prey handling of giant cuttlefish (Sepia apama) by Indo-Pacific bottlenose dolphin (Tursiops aduncus).Prey: (a) pinned to substrate and killed; (b) lifted towards surface; (c) beaten with snout to release ink; (d) consumed whole.
Mentions: Pinned thrust kill: A rapid downward vertical thrust was effected by the dolphin using a powerful tail beat (Fig. 1b, 2a), accompanied by a whole body twist that broke the cuttlebone and/or cephalic cartilage (with a loud click audible to divers), instantly killing the cuttlefish.

Bottom Line: The deceased cuttlefish was then returned to the seafloor, inverted and forced along the sand substrate in order to strip the thin dorsal layer of skin off the mantle, thus releasing the buoyant calcareous cuttlebone.This stepped behavioural sequence significantly improves prey quality through 1) removal of the ink (with constituent melanin and tyrosine), and 2) the calcareous cuttlebone.Aspects of the unique mass spawning aggregations of giant cuttlefish in this region of South Australia may have contributed to the evolution of this behaviour through both high abundances of spawning and weakened post-spawning cuttlefish in a small area (>10,000 animals on several kilometres of narrow rocky reef), as well as potential long-term and regular visitation by dolphin pods to this site.

View Article: PubMed Central - PubMed

Affiliation: Sciences, Museum Victoria, Melbourne, Victoria, Australia. jfinn@museum.vic.gov.au

ABSTRACT
Dolphins are well known for their complex social and foraging behaviours. Direct underwater observations of wild dolphin feeding behaviour however are rare. At mass spawning aggregations of giant cuttlefish (Sepia apama) in the Upper Spencer Gulf in South Australia, a wild female Indo-Pacific bottlenose dolphin (Tursiops aduncus) was observed and recorded repeatedly catching, killing and preparing cuttlefish for consumption using a specific and ordered sequence of behaviours. Cuttlefish were herded to a sand substrate, pinned to the seafloor, killed by downward thrust, raised mid-water and beaten by the dolphin with its snout until the ink was released and drained. The deceased cuttlefish was then returned to the seafloor, inverted and forced along the sand substrate in order to strip the thin dorsal layer of skin off the mantle, thus releasing the buoyant calcareous cuttlebone. This stepped behavioural sequence significantly improves prey quality through 1) removal of the ink (with constituent melanin and tyrosine), and 2) the calcareous cuttlebone. Observations of foraging dolphin pods from above-water at this site (including the surfacing of intact clean cuttlebones) suggest that some or all of this prey handling sequence may be used widely by dolphins in the region. Aspects of the unique mass spawning aggregations of giant cuttlefish in this region of South Australia may have contributed to the evolution of this behaviour through both high abundances of spawning and weakened post-spawning cuttlefish in a small area (>10,000 animals on several kilometres of narrow rocky reef), as well as potential long-term and regular visitation by dolphin pods to this site.

Show MeSH