Subterranean Fishes of the World

4894

2015

Mediterranean Marine Science

270

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Gouania willdenowi is a stenoecious clingfish species endemic to the Mediterranean Sea, whose habitat is restricted to interstices of infralittoral pebbles. The biology of the species is almost unknown with the exception of a few works documenting its habitat utilization along the western shores of Mediterranean (Pérès, 1967; Patzner, 1999; Hofrichter & Patzner, 2000). The fish lead a very hidden life from the waterline mark to a depth of 2 m, and escape from moving pebbles to lower parts of the boulders during stormy weathers (Pérès, 1967); it has never been observed outside the layer of pebble banks (Patzner, 1999). An exceptional study by Hofrichter & Patzner (2000) also indicated the presence of the blunt-snouted clingfish in the lower tidal zone, but the authors were hesitant to define this behaviour as amphibious, because the deeper layers of the pebbles, where it lives, still contain some water. During a macrozoobenthic sampling survey carried out in a protected cove (36.2519°N, 30.1175°E; Eastern Mediterranean Sea, Turkey; Fig. 6a), 26 pale coloured individuals of G. willdenowi with total lengths ranging from 21 to 30 mm were observed in the middle and high tidal zones (Fig. 6b-c). All the fish were encountered within the moist lower pebble layer, constituted of pebbles having with a maximum diameter of 2 cm. The blunt-nose clingfish individuals were relatively quiet and inactive while out of water and do not appear to be distressed, even after exposure to air for over 2 hours (Fig. 6d). The available in situ observations are in agreement with the relevant descriptions of passive amphibious emergence behaviour (Martin, 2014), in which the underlying reasons are probably associated with a vast number of biotic and abiotic factors, yet to be elucidated. Such an unusual terrestrial endurance of G. willdenowi has not been reported previously from the eastern coasts of the Mediterranean Sea coasts and thus represents a novel finding worth of further meticulous study.

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