(Risso's dolphin  (Grampus griseus

 

    

 

Meaning of species name is "grey". World-wide distribution, similar to the false killer whale.

At sea identification: Adult body length is 4 meters, at the upper range of the "dolphin" terminology. Grey color than brightens with age, mainly on account of scarring by conspecific tooth rakes and octopus arm suckers, to the point of looking white. Round, beakless head with a distinct central fold from blow-hole to upper lip. Marked difference between the broad and stout front and the slender rear of body. Very prominent and tall triangular dorsal fin (up to 50 cm), possibly with the highest ratio to body length of all cetaceans. Usually sighted over steep shelf slopes, at depths of 300-1,000 m, in groups of tens. Not too sociable, but allows close approach. When approaching vessels, will swim alongside, rather than bow-ride. May dive up to 30 min, but usual dive time is 2 min, with up to 10 inter-dive ventilations.

Identifying marks on land: Apart from the above, adults lack teeth in the upper jaw and bear 1-7 teeth on each half of the lower.

Nocturnal feeders, mainly on vertically migrating squid. Common in the Mediterranean and in our region (sightings of large groups with calves as well as strandings of live calves), more so in the north. Very common in the gulf of Eilat.

Additional facts:

Adult weight: 400 Kg.

Newborn length is 1.5 meters.

Life expectancy: Over 30 years.

 

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