Nagasawanus, Uyeno, Daisuke, 2015

Uyeno, Daisuke, 2015, Systematic revision of the pennellid genus Creopelates Shiino, 1958 (Copepoda: Siphonostomatoida) and the proposal of a new genus, Zootaxa 3904 (3), pp. 359-386 : 375

Genus Nagasawanus n. gen.

Diagnosis of postmetamorphic adult female. Body long, comprising cephalothorax, neck region and trunk; junction of neck and trunk slightly curved. Cephalothorax bearing paired round antennary processes and paired smooth spherical posterolateral lobes; rostrum projecting, narrow. Neck region narrow, curved near junction with trunk; second and third pedigers clearly segmented. Trunk pyriform, longer than wide, with anterior end narrowing towards neck region. Abdomen conical, located between oviducal pores. Egg-sac uniseriate, coiled or curved.

Antennule unsegmented, bearing more than 28 setae and 1 distal aesthetasc, 2 of distal setae sharing common base. Antenna 3-segmented, chelate, typical pennellid; proximal segment unarmed; middle segment bearing one pointed protrusion on inner medial margin, terminal segment claw-like bearing small basal element on posterior surface. Mouth tube, maxillule, and maxilla located near base of antenna on anterior part of ventral surface of cephalothorax. Maxillule bilobate, composed of knob-like lobes; inner lobe bearing one seta; outer lobe bearing two setae. Maxilla 2-segmented; proximal segment bearing single subterminal pointed process; terminal segment forming elongate claw, incompletely subdivided. Maxilliped absent.

Legs 1 and 2 biramous. Legs 3 and 4 uniramous. Legs 1–4 evenly arrayed along posterior part of cephalothorax to neck region. Armature formula of legs 1–4 as follows:

Protopod Exopod Endopod Leg 1 1–1 1–1; 7 0–1; 7 Leg 2 1–0 1–1; 7 0–1; 7 Leg 3 1–0 0–0; 6 Absent Leg 4 0–0 0–0; 5 Absent Adult male. Unknown.

Type species. Nagasawanus akinohama n. sp. by original designation.

Remarks. Nagasawanus n. gen. clearly differs from other pennellid genera by its possession of the following combination of characters: antennary processes and cephalic lobes rounded without branched fringes; neck region without any processes; maxilla with claw-like terminal segment without spinules.

Etymology. The generic name “ Nagasawanus ” is dedicated to Prof. Kazuya Nagasawa, an outstanding aquatic parasitologist.