Body elongate, compressed laterally. Head small or large, 
variously compressed. Snout short. Eye large, usually greater than 
snout and well advanced in head, also usually impinge on upper profile of 
head. Mouth terminal, oblique, with jaws subequal. Lips usually broad 
and fleshy. Maxillary extends below eye. Several rows of teeth in each 
jaw, outer row larger and less numerous. Interorbital narrow, eyes closely 
set. Preopercle entire. Scales ctenoid, large, 22 to 28 in lateral 
series. Head and predorsal naked, latter without median keel. Dorsals 
divided, first with 6 spines, second dorsal with spine and 8 to 10 rays. 
Anal with spine and 7 to 9 rays. Caudal rounded behind. Pectoral large, 
lateral, reaches anal. Ventral subequal with pectoral, narrow, well 
separated, ends of rays as well as those of lower pectoral rays fringed. 
Minute gobies of the Indo-Pacific, most less than one inch in 
length. They are very abundant in the coral reefs of Oceania. Owing to 
their small size they are able to live in the smallest crevices of corals 
and other marine animals. They are usually best secured by breaking up 
pieces of coral over a canvas or cloth. Some also are taken in surface 
hauls of plankton and other masses of marine life, by means of a light at 
night, sometimes over deep water. 
Trimma differs chiefly in its firmer and more solid body texture, 
and the predorsal region fully scaled. 
