Monday, February 6, 2012
The birrin are at home in water, and many engage in swimming recreationally with or without the aid of SCUBA systems. Diving activities are associated with risks: as in this potentially dangerous encounter with the creature seen here.
Evolved from the same land-living ancestor as the birrin the Sardu, as they are locally known, are air breathing creatures of great strength and predatory skill. They range across most regions of the ocean, hunting diverse prey depending on local resources, and adjusting their strategies accordingly. All however rely on an extraordinary ability to generate powerful electric shocks via organs housed in their huge, elongated horizontal jaws. This allows them to stun entire schools of smaller organisms to consume at their leisure, or to probe their jaws into soft mud and detect, flush out kill benthic creatures of considerable size. The electrogenic organs also have a social purpose; and mating individuals compete to show both their ability to generate electricity, and to withstand the shocks of their adversaries. The small creatures that accompany sahdy as commensals must also be tolerant of this hazard, and most swim to a safe distance during the closing stages of a hunt, moving in to feast on the scraps afterwards.
The birrin diver seen here may seem in danger, however it is experienced with the local sardu and knows it is not a part of their prey search image; the constant stream of bubbles generated by the SCUBA gear and bright wetsuit look so unlike the large bottom dwelling creatures it usually hunts that it does not view the birrin as food.