Enterophilus, Kim, 2000

Kim, Il-Hoi, 2000, Poecilostomatoid Copepods from an Intertidal Mud Flat in the Yellow Sea, Journal of Natural History 34 (3), pp. 367-432 : 389-390

Enterophilus n. gen.

Diagnosis. Synaptiphilidae . Body consisting of cephalothorax, three prosomites and ®ve-segmented (in female) or six-segmented (in male) urosome. Cephalothorax and ®rst two pedigerous somites with well developed epimera. Caudal rami greatly dilated, bearing four caudal setae, with terminal one enlarged. Antennule sixsegmented, armature formula of 5, 14, 9, 4 +1 aesthetasc, 2 +1 aesthetasc, and 7 +1 aesthetasc; without sexual dimorphism. Antenna four-segmented, with armature formula of 1, 1, 1 +1 claw, and 3 +4 claws; claw of third segment very strong; claws of terminal segment with spatulate tip. Mandible with only one thick element. Maxillule armed with three setae. Maxilla two-segmented; ®rst segment with one distal spine; second segment armed terminally with one spine and three setae. Maxilliped has unsegmented digitiform process in female, but well-developed in male. Legs 1±4 with three-segmented exopod and two-segmented endopod; setae and spines reduced in number. Legs 1±5 without sexual dimorphism. Basal segment of leg 5 incorporated into somite. Living in alimentary canal of holothurians.

Etymology. The generic name is derived from the Greek enteron (= intestine) and philos (= loving). It alludes to the discovery of the new genus in the digestive tract of the holothurian. The gender is masculine.

T ype species. Enterophilus cercomegalus n. sp.

Remarks. Along with the genera Presynaptiphilus and Synaptiphilus , the new genus is classi®ed in the Synaptiphilidae . This family is characterized by the primitive, clausidiid type maxilla and male maxilliped; transformed female maxilliped; reduced setation on the legs; and four-segmented antenna with a strong claw on the third segment. Of the other two confamilial genera, Enterophilus is closer to Synaptiphilus than to Presynaptiphilus in the following characteristics: (1) three-segmented exopod and two-segmented endopod on legs 1±4; (2) antenna with one claw and one seta on the third segment, and four spatulate elements on the terminal segment; (3) nearly identical maxilla and male maxilliped; and (4) equally reduced number of setae on the maxillule.

However, the new genus can be di erentiated from Synaptiphilus by the following features: (1) mandible with only one element; (2) female maxilliped reduced to a non-functional process; (3) greatly expanded caudal rami, with an enlarged caudal seta; and (4) free single segment of leg 5 resulting from fusion of original ®rst and second segments.