Enneophyllus McLaughlin, 1997

Komai, Tomoyuki, 2017, Enneophyllus ecarina, a new species of scaphopod shell dwelling hermit crab (Crustacea: Decapoda: Anomura: Paguridae) from deep-sea off the Ryukyu Islands, southern Japan, Zootaxa 4269 (4), pp. 593-600 : 593-594

Genus Enneophyllus McLaughlin, 1997

[New Japanese name: Hoso-tsutsu-yadokari-zoku] Enneophyllus McLaughlin, 1997: 439 ; 2003: 122.

Type species. Enneophyllus spinirostris McLaughlin, 1997 , by original designation and monotypy.

Emended diagnosis. Nine pairs of biserial gills (2 arthrobranchs on each pereopod 1–4 + 1 pleurobranch on thoracomere 7 (above arthrobranchs of pereopod 4); no arthrobranchs on maxilliped 3. Rostrum well developed, strongly depressed, with epirostral spine. Ocular acicles small, simple. Maxilliped 3 with crista dentata on ischium somewhat reduced, consisting of row of widely spaced acute teeth; no accessory tooth. Chelipeds unequal, right appreciably larger. Pereopod 4 weakly semichelate, propodal rasp with 1 row of corneous scales; no preungual process on dactylus. Coxa of left pereopod 5 of male with long, basally stout sexual tube directed exteriorly and curved dorsally across pleon from left to right; coxa of right without sexual tube, only gonopore present. Female with paired gonopores on coxae of pereopods 3. Thoracic sternite 6 with very small anterior lobe. Pleon straight, greatly elongate (more than 3 times of carapace length); males with unpaired pleopods 3–5, females with unpaired pleopods 2–5, no paired pleopods. Telson with faint lateral indentations; terminal margins oblique.

Remarks. Examination of the female paratype of the new species clarified some female characteristics, previously not known for the type species of Enneophyllus , including the absence of paired pleopods 1 and the presence of unpaired pleopods 2–5, and the presence of paired gonopores on the coxae of pereopods 3.

Affinities of Enneophyllus to Enneobranchus and Enneopagurus have been already discussed by McLaughlin (1997). The new species shares with E. spinirostris the strongly depressed rostrum with an epirostral spine, representing an unusual feature for Paguridae , and thus, this presumably apomorphic character might also be diagnostic at the genus level.