Associations of the gobies Eutaeniichthys gilli and Gymnogobius scrobiculatus with burrows of the mud shrimp Upogebia yokoyai at low tide

Abstract

The gobies Eutaeniichthys gilli and Gymnogobius scrobiculatus were collected from burrows of the mud shrimp Upogebia yokoyai at low tide by digging and using a yabby pump from April 2007 to September 2008 at Susaki Bay, Kochi Prefecture, Japan. A total of 144 E. gilli and 103 G. scrobiculatus were collected. Densities of E. gilli and G. scrobiculatus collected by digging were 1.4 and 1.0 ind. per 0.25 m 2 , respectively. Symbiotic prevalences of E. gilli and G. scrobiculatus in mud shrimp burrows the percentage of burrows occupied by E. gilli and G. scrobiculatus collected using the yabby pump were 2.7 and 2.6, respectively. Juveniles of E. gilli were collected in June; juveniles of G. scrobiculatus were collected in April. Adults of both species were collected year round. The present study clearly shows that E. gilli and G. scrobiculatus both use Upogebia burrows at low tide. In order to conserve these threatened and near-threatened gobies, conservation of this habitat as well as the mud shrimp might be needed.