Eisothistos species

Knight-Jones, E. W. & Knight-Jones, Phyllis, 2002, Four new species of Eisothistos (Anthuridea: Isopoda) from tubes of Spirorbidae (Serpuloidea: Polychaeta), Journal of Natural History 36 (12), pp. 1397-1419 : 1398-1400

Eisothistos species previously described

These (mostly female) are listed below in alphabetical order of species names, with notes on some peculiarities of each and references to gures of the new species, all of which are closely related to those preceded here by asterisks (termed ‘sibling’ species in Discussion after gure 9).

(a) E. andamanensis Kensley and Schotte, 2000 . Ten, up to 6 mm long, three in a serpulid tube, from west coast of Thailand. Telson with row of mid-line spines and spinules, hind margin with many small teeth, two small adcentral setae, anked by pair of large plumose setae and two pairs of smaller setae (non-plumose). Pereopods 1 and 7 with very long setae on each basis and ischium. Each pereopod 2 with nine ischial studs.

(b) E. anomala (Kensley, 1980, as Heteranthura ). One ca 3 mm long, with sponges and coelenterates, 1 m depth oV Madagascar. No keel spines, telson hind margin rounded with many small teeth and three pairs of plumose setae. Antennule with an aesthetasc arising from each of two most distal articles, not from two penultimate articles as in most Eisothistos (e.g. gure 2C). Each pereopod 2 bears seven ischial studs.

(c)* E. antarcticus VanhöVen, 1914 (best described by Wägele, 1984). Several 4–5 mm long from> 200 m depths in Antarctic. Telson with keel spines in several rows (as in gure 1F, K), hind margin rounded with many teeth and four pairs of setae. Each seta of smallest marginal pair may be termed a companion seta, since it accompanies one of the largest setae, arising from the same marginal notch (as shown here in gures 1F, 2K, 4B, 8H). Setae of largest pair plumose, separated from each other by only two teeth of hind margin. Each pereopod 3 with 14 ischial studs.

(d) E. atlanticus . VanhöVen, 1914. One 5 mm long from Porto Grande on St Vincent, Cape Verde islands. Description inadequate.

(e) E. bataviae Kensley and Poore, 1982 . Several 2–3 mm long from coral rubble on old wreck 1.3 m depth at 28ss43¾S oV W. Australia. Telson without keel spines, hind margin rounded with many teeth, one pair of plumose setae and several simple setae. Antennule with both aesthetascs arising from terminal article. Pereopods with many long setae on and near ischia. Uropodal exopod main fang with four short dorsal spines .

(f) E. besar Müller, 1992 . Six 1.7–2.1 mm long from dead coral, 1–2 m depths, Tioman Archipelago, Malaysia. Hind telson with small dorsal setae in adlateral positions (as in gure 4B). Main fang of uropodal exopod bears recurved tooth on dorsal surface. Fertilized female misidenti ed as ‘preparatory male’ (see Discussion adjoining gure 9).

(g)* E. corallinae Kensley and Schotte, 2000 . Eight females and one male, lengths 2–3 mm, from intertidal algal turf, Aldabra. Female antennules have an aesthetasc on each article 5 and 6 of agella with seven articles. Telson as in (c) above but with fewer keel-spines, in one row, whilst largest pair of hind setae lack companion setae and may not be plumose.

(h) E. crateris Kensley, 1976 . Male 3 mm long, from ooded crater of St Paul Island, Indian Ocean. First three pleonites with rounded sides, like pereonites, as usual in males (see gure 7A, D).

(i)* E. macrurus Wägele, 1979 . Many <3.5 mm long, from tubes of serpulid Vermiliopsis , depths 5– 40 m. Gulf of Naples. Telson with keel spines and hind margin as in E. antarcticus (see above), but setae of plumose pair are separated from each other by four to six marginal teeth (gure 1F, K). Anterior pereonites of postpartum females bear many long setae on sides and back (gure 1B).

(j) E. maledivensis Wägele, 1979 . Three females 1.5–3 mm long, from coral 17–35 m depths, Maldive Islands. Telson with three pairs plumose setae, the adcentral pair with companion setae (as in gure 1F), pereopod 2 ischium with ve studs (like distal group in gure 1D), but antennule 1 with three aesthetascs, one on each of three subdistal articles.

(k) E. minutus Sivertsen and Holthuis, 1980 . Two, 0.8 and 0.9 mm long, depths 0–5 m oV Tristan da Cunha. Incompletely described, but pereopod 1 is shown with a fringe of scales along the ventral margin of propodus. Usually pereopod 1 lacks such a fringe, but male of E. crateris had one ( Kensley, 1976), as have the males in gure 7A, E.

(l) E. moreirae (Pires, 1981, as Heteranthura ). Three females 2.7 mm long, from algae 3 m deep near Ubatuba, South-East Brazil. Telson lacks keel spines, hind margin with ve pairs of setae alternating with teeth, the largest pair plumose and one of the teeth median, somewhat like gure 2J but with more setae on telson margin and none on its dorsal surface.

(m) E. neoanomalus ( Shyamasundari et al., 1991, as Heteranthura ). Three females 9 mm long, from sponges on intertidal rocks, southern India. Telson without keel spines, hind margin with three pairs of plumose setae alternating with teeth. Anterior to these are two small dorsal setae in adlateral positions, as in gure 4B.

(n) E. nipponicus Nunomura, 1984 . Four, 3.6–4.8 mm long, from rocks with algae and serpulids in Osaka Bay. Telson without keel spines, hind margin narrowing posteriorly with many small setae but no teeth.

(o) E. petrensis Kensley, 1984 . Many 2–4.3 mm long, from coral reef rubble 0.1–36 m depths in West Indies. Telson and ischial studs of pereopod 2 ‘like those of E. anomala ’. Female with 13 plumose setae on fused rami of pleopod 1, alternating with marginal spines. More records in Müller (1991).

(p)* E. pumilus Wägele, 1979 . Seven 1.6–3.5 mm long, from tubes of Salmacina (Serpulidae) , depths 6–30 m near Naples. Telson like gure 2H, K, relatively narrow, but with four teeth separating the plumose setae and with keel spines sometimes in double row.

(q) E. societensis Müller, 1990b . One 3.8 mm long in dead coral 1–2 m depths oV Moorea, 17ss32¾S, 149ss50¾W. Telson without keel spines. Tail-fan teeth very small, but fringe setae numerous, remarkably so on exopods.

(r)* E. tayronae Müller, 1990a . One 2.47 mm long, from 2–3 m depth in Caribbean, 11ss18¾N, 74ss10¾W. Hind telson as in gure 4B, but with three teeth separating the plumose pair of setae. Main spine of each uropodal exopod very long.

(s)* E. teri Kensley and Snelgrove, 1987 . Many 1.3–3.2 mm long, from coral 5–14 m deep, west of Barbados. Antennule basal article has leaf-like process, as in gures 5A, 6A. Ischium of pereopod 2 bears 11 marginal ridges. Female hind telson somewhat like gure 4B, but with very large posterior keel teeth. Uropodal exopod main fang bears a recurved tooth dorsally, as in E. besar .

(t) E. vermiformis Haswell, 1884 . Seven, all female ( Wägele, 1979: 5) up to 12 mm long, from Vermilia tubes on shore near Sydney, Australia. Telson hind margin gured as an almost straight transverse line, with numerous small setae. Ischium of pereopod 2 with row of 17 studs. Pereon of one bore numerous long pinnate hairs on each side.