Ithyleucon, Corbera, Jordi, 2012

Corbera, Jordi, 2012, Rare and new cumaceans (Crustacea, Peracarida) from the southern margin of the Cap Ferret Canyon (Bay of Biscay), ZooKeys 235, pp. 73-85 : 77

Ithyleucon gen. n.

Diagnosis.

Pseudorostrum extending anterodorsally and upturned; antenna 1 geniculate between peduncle article 1 and 2; accessory flagellum longer than main flagellum article 1; female with exopods on maxilliped 3 and pereopods 1-3; male with exopods on maxilliped 3 and pereopods 1-4; pereopod 2 ischium very short; uropod endopod 2-articulate; male with two pairs of pleopods.

Remarks.

The shape of the carapace and the position of the pseudorostrum of Ithyleucon gen. n. resemble those of Pseudoleucon Zimmer, 1903. However, Ithyleucon differs from the latter by 1) the size of the uropod endopod, which is longer than the peduncle and of similar length as the exopod (i.e., as long as the peduncle and certainly shorter than the exopod in Pseudoleucon ) and by 2) the antenna 1 accessory flagellum, which is longer than the main flagellum article 1 (shorter in Pseudoleucon ). Although these two features, as well as the geniculated antenna 1, are in agreement with the diagnosis of Bytholeucon Watling, 1991, the anterolateral corner is strongly angular in this genus and the known males observed up until now have had only one pair of pleopods.

In addition to these morphological differences, the only two known Pseudoleucon species also show divergence in terms of their ecology and biogeography. They inhabit shallow bottoms of the northeastern Pacific and a phylogenetic relationship with the genus described herein seems to be highly unlikely.

Etymology.

From the Greek ithys, meaning upright, referring to the position of the pseudorostrum, and Leucon , the stem genus. Gender masculine.

Type species.

Ithyleucon sorbei sp. n.