Asterostegus Mortensen, 1933

Okanishi, Masanori & Fujita, Toshihiko, 2014, A taxonomic review of the genus Asterostegus (Echinodermata: Ophiuroidea), with the description of a new species, European Journal of Taxonomy 76, pp. 1-18 : 3-4

Genus Asterostegus Mortensen, 1933

Asterostegus Mortensen, 1933a: 4, 40; 1933b: 297.

Asterostegus – Fell 1960: 10. — McKnight 2003: 385-386.

Type species: Asterostegus tuberculatus Mortensen, 1933 , by monotypy.

Diagnosis

Arms simple, not branching. Tubercles present on radial shields and aboral arms. Oral interradial plates present on distal side of adoral shields. Teeth triangular. Oral papillae domed, granule-shaped, present laterally on the jaws. Tentacle pores with two (rarely three) arm spines from fourth arm segment. Oral side of vertebrae with an oral bridge. Lamina of distal arm spines smooth.

Remarks

Based on this study, Asterostegus is currently composed of three species, A. sabineae sp. nov., A. maini McKnight, 2003 and A. tuberculatus Mortensen, 1933 . A tabular key to the species of Asterostegus is provided ( Table 1 ).

Species of this genus are distributed in the Indian Ocean, off Madagascar ( Mortensen 1933b) and in the Western Pacific, south-east of New Caledonia ( McKnight 2003), at a depth of 382-500 m ( Fig. 1 ).

Figures

Fig. 1. Known distribution of Asterostegus maini McKnight, 2003, A. sabineae sp. nov., and A. tuberculatus Mortensen, 1933 are indicated by square, circle and star shaped symbols respectively. Solid symbols indicate the type locality of each species.

Tables

Table 1. A tabular character key to the species of Asterostegus.

	Tubercles on aboral surface of the disc			Numbers and arrangement of oral interradial plates
Species	Number and arrangement of tubercles on aboral disc	Number of tubercles on top of each lateral bar	Length of tubercles on periphery of radial shields
A. sabineae sp. nov.	Two to four, in a line on the radial shield	One or two	ca. 1–1.2 mm	One in each interradius
A. maini McKnight, 2003	Ca. 10, only on periphery of radial shield	Three to five	ca. 250–300 µm	Three to five arranged in one row
A. tuberculatus Mortensen, 1933	Scattered over entire radial shield and peripheral part of aboral disc	Two or three	ca. 350 µm	Five to eight arranged in two rows