Zygosiphon, CALMAN, 1907

Haye, Pilar A., 2007, Systematics of the genera of Bodotriidae (Crustacea: Cumacea), Zoological Journal of the Linnean Society 151 (1), pp. 1-58 : 22-23

ZYGOSIPHON CALMAN, 1907 A

Type species: Zygosiphon mortenseni Calman, 1907a

Body: Carapace shorter than abdomen and similar in length to peraeon; abdomen longer than carapace and peraeon together.

Cephalothorax: From dorsal view the carapace appears laterally compressed in the medial portion. Carapace with mid-dorsal ridge. Pseudorostral lappets extend beyond frontal lobe; meet in midline or partially meet leaving a suture between them. Antennal notch as a subacute or acute incision. Anterolateral corner with subacute or acute tooth. Branchial siphons long, extending much beyond pseudorostrum and not fused in the midline. Frontal lobe 1/4–1/3 of carapace length; wider than long; with anterior margin notched; with ocular pigment and eye lenses.

Antenna 1 with basal article of the peduncle straight; as long as the other two articles together. Main flagellum bi-articulated; with two aesthetascs in distal-most article. Accessory flagellum uniarticulated. Antenna 2 in males reaching end of pleon; with sensory setae on anterior margin of article four. Antenna 2 in females with one article.

Maxilliped 3 basis geniculate; extended dorsodistally over ischium beyond the articulation of the ischium and merus. Ischium longer than merus. Merus extended dorso-distally over carpus. Carpus equal to or shorter than propodus and dactylus together.

Peraeon: Peraeonite 2 may have ventrolateral expansion, and when present the expansion does not override other somites. Peraeonite 3 extended backwards overriding peraeonite 4. Peraeonite 4 with ventrolateral expansion overriding peraeonite 5.

Peraeopod 1 with basis arcuate; inner apical angle extended to form a convex process; carpus shorter than propodus. Peraeopod 2 with ischium; dactylus longer than propodus. Peraeopod 4 with ischium.

Pleon: Articular pegs may be present. Pleonite 5 as long or longer than pleonite 6. Pleonite 6 longer than wide; shorter than peduncle of uropod. Wide portion of distal end of pleonite 6 well extended between the bases of the uropods; with rounded apex. Anal plates extend posteriorly beyond distal margin of pleonite 6.

Uropod endopod bi-articulated; proximal article longer than distal one. Uropod exopod with proximal article shorter than distal article. Peduncle of uropods longer than rami; exopod longer than endopod. Males with five pairs of pleopods.

Species included:

1. Z. mortenseni Calman, 1907a

Distribution: Indo-West Pacific from 7 to 22 m.