Length in females 20-30 mm (forma typicus) or 10-15 mm (forma bulbosus, Oxycephalus piscator 2), in males to 27 mm (Oxycephalus piscator 1). Females as two forms with different appearances: large forma typicus with elongate head, slightly convex dorsally (Oxycephalus piscator 4), and ventrally without clear border between triangular rostrum and main part of head (head about twice as long as high); moderately small forma bulbosus with more globular head, strongly convex dorsally, ventrally with beak-like rostrum (head 1.5 times as long as high). Males with same general appearance as female f. typicus, but with straighter ventral and dorsal margins of head. Head subequal to pereonites I-VI combined, in female f. bulbosus even with whole pereon. P I with linear ART 2 longer than distal ART combined; anterior margin of ART 5 smooth, posterodistal process of this ART sharp, broadly triangular with both margins strongly serrate (especially inner margin), subequal to broadly oval ART 6. P II longer than P I (Oxycephalus piscator 3); ART 2 linear, longer than distal ART combined; anterior margin of ART 5 smooth, straight, posterior margin almost straight, posterodistal process sharp, narrowly triangular; subequal to almost linear, slightly curved ART 6; inner margins of chela with rare blunt denticles. Chela of P I and II with few setae. ART 2 of P V-VI broad, suboval, with slightly concave distal margin. Epimeral plates with one denticle on each posterodistal corner. Telson serrate in distal part.