Ammotrypanella mcintoshi, Schüller, Myriam, 2008

Schüller, Myriam, 2008, New polychaete species collected during the expeditions ANDEEP I, II, and III to the deep Atlantic sector of the Southern Ocean in the austral summers 2002 and 2005 — Ampharetidae, Opheliidae, and Scalibregmatidae, Zootaxa 1705, pp. 51-68 : 58-59

Ammotrypanella mcintoshi sp. nov.

( Fig. 4A–B )

Holotype. ANDEEP III, st. 16-10, Southern Atlantic, off South Africa, 26 January 2005, 41°07.55’ S, 9°55.94’E, 4720 m, EBS, ZMH P- 24753.

Paratypes. ANDEEP III, st. 21-7, Southern Atlantic, 29 January 2005, 47°39.87'S, 04°15.79'E, 4574 m, EBS, 1 specimens, ANDEEP III, st. 59-5, Atlantic Sector Southern Ocean, 14 February 2005, 67°30.75'S, 00°00.23'W, 4651 m, EBS, 1 specimens, ZMH P- 24754.

Additional material. 16-10 (2), 74-6 (2), 110-8 (3), 121-11 (1).

Etymology. The name is chosen in honour of W.C. McIntosh who defined the genus Ammotrypanella in 1879.

Diagnosis. The diagnostic character of this species is the lack of an anal tube.

Description. Holotype complete, body long and thin, 6 mm long and 0.5 mm wide for 35 chaetigers.

A small species of 5–16 mm length and 0.5–1 mm width; number of chaetigers about 30–35 or more, very variable. With ventral and lateral groove along whole length of body. Posterior body region bilaterally flattened. Color in alcohol white to a light tan.

Prostomium conical, bearing a short palpode. Peristomium a thin ring around the lips. First subsequent segment apparent as a narrow ring from above, without chaetae. Nuchal organs indistinct narrow lateral grooves, eyes absent ( Fig. 4A ).

Anterior 8–10 parapodia button shaped with long, stiff chaetae in bushy fascicles. Following parapodia indistinct, embedded in lateral groove. Posterior parapodia more distinct with long, straight chaetae. All chaetae simple capillaries.

Branchiae present in third quarter of body, all of similar length, flat with wide base, tapering to top.

Posterior abranchiate chaetigers reduced in length, close to each other. Pygidium without anal tube ( Fig. 4B ).

Remarks. The species is most similar to the type species of the genus Ammotrypanella , A. arctica . In contrast to all other species of the genus the species lacks an anal tube and thus can easily be recognized at first sight.

Distribution. Southern Atlantic to Atlantic sector of Southern Ocean, 1047–4720 m

Figures

FIGURE 4. A – B Ammotrypanella mcintoshi sp. nov. A. anterior segments, B. posterior segments; C – D. Ophelina robusta sp. nov. C. anterior segments, D. posterior segments; E – F. Ophelina ammotrypanella sp. nov. E. anterior segments, F. posterior segments.