Echiniscus elaeinae, Pilato & Binda & Lisi, 2005

Pilato, Giovanni, Binda, Maria Grazia & Lisi, Oscar, 2005, Remarks on some Echiniscidae (Heterotardigrada) from New Zealand with the description of two new species, Zootaxa 1027 (1), pp. 27-45 : 27-45

Echiniscus elaeinae sp. nov. ( Figs. 7 , 8 )

Material examined: South Island, Open Bay Island, Taumaka I: two specimens from Physcia elaeina (lichen) on Hebe elliptica .

We examined two specimens named Echiniscus spiniger Richters, 1904b by Horning et al. (1978), but in our opinion they belong to a new species here described and named Echiniscus elaeinae sp. nov.

Description of the holotype: Body length 240 m, eyes absent; median plate 3 present; plate sculpture uniform consisting of circular dimples, the largest of which (diameter up 1.8 m) are present on the median plates 1 and 2 and on the posterior portion of the paired plates II and III ( Fig. 7 B ). Head plate with an anterior notch; neck plate very narrow ( Fig. 7 A ); scapular plate composed of three pieces: a larger central one and two smaller lateral ones ( Fig. 7 A ); paired plates II and III with a transversal smooth band; anterior portion of these plates with an oblique smooth band ( Fig. 7 A, B ); as in other species of the genus, a sculptured band is present between the median plates and the paired plates; a less evident sculpture is present laterally to the median plates; ventral surface with very fine, almost invisible, dots.

In addition to the buccal cirri and to the filaments A, long lateral spines C, D, E and dorsal spines Cd and Dd are present ( Figs. 7 B , 8 A ). The dimensions of some structures are indicated in Table 1.

First pair of legs with a small spine; hind legs with a papilla and a dentate fringe ( Fig. 7 B ). Each internal claw with a thin, straight spur directed downwards ( Fig. 8 B ).

Etymology: The name elaeinae derives from the name, Physcia elaeina , of the lichen where the holotype was found.

Remarks: Echiniscus elaeinae sp. nov. differs from E. spiniger Richters, 1904b , as follows: plate sculpture uniform and very different from the merokensis type; median plate 3 present, paired plates II and III with a transversal smooth band; spine B absent, spurs of internal claws thinner and straight.

Horning et al. (1978) drew a specimen named E. spiniger with spine B, but in the text it was not specified whether this appendage may be absent in some specimens; therefore we cannot state whether they found specimens belonging to two species but did not note that one of them lacks B, or whether they found only one species where the spine B may be present or absent. The specimens we examined differ from E. spiniger in many characters and surely do not belong to this species.

The new species differs from E. spinulosus ( Doyère, 1840) in the following features: more regular and denser plate sculpture; eyes absent; median plate 3 present; terminal plate not faceted; lateral spines longer; spurs of internal claws thinner and straight.

It differs from E. virginicus Riggin, 1962 in the following features: plate sculpture more regular and not double; spurs of internal claws thinner and straight.

E. elaeinae sp. nov. is very similar to E. jamesi Claxton, 1996 but we examined four paratypes of this species, kindly sent by Sandra Claxton, and we noted that the new species differs from E. jamesi in the following features: eyes absent; dorsal plates with a simple, not double, sculpture; lateral appendages are long spines while in E. jamesi they are filaments up to 100 m long often with slight terminal swelling; dorsal spines Cd and Dd present; spurs of internal claws less developed.

The presence of E. spiniger in New Zealand needs to be confirmed.

Figures

FIGURE 7. Echiniscus elaeinae sp. nov. (holotype): A, B, details of the plate sculpture. Scale bar = 10 m.

FIGURE 8. Echiniscus elaeinae sp. nov. (holotype): A, habitus (Scale bar = 30 m); B, claws of the hind legs (Scale bar = 10 m).