Glyphochaeta laudieni, Bick, 2005

Bick, Andreas, 2005, A new polychaete genus and species of the Kongsfjorden, Spitsbergen, Svalbard, Journal of Natural History 39 (32), pp. 2987-2996 : 2989-2993

Glyphochaeta laudieni sp. nov.

( Figures 1–3)

Type material

Holotype: Svalbard, Spitsbergen , Kongsfjorden , BlomstrandhalvØya , marine grotto near Hansneset (78 ° 59.08 9 N, 11 ° 57.43 9 E), grotto wall, from among Bryozoa colonies, 4 m depth, 4 September 2004 ( ZSRO-P1649 ) . Paratypes: Svalbard, Spitsbergen , Kongsfjorden , BlomstrandhalvØya , marine grotto near Hansneset (78 ° 59.08 9 N, 11 ° 57.43 9 E), grotto wall, from among Bryozoa colonies, 4 m depth, 4 September 2004, four specimens ( ZSRO-P1650 ) ; Svalbard, Spitsbergen , Kongsfjorden , BlomstrandhalvØya , marine grotto near Hansneset (78 ° 59.08 9 N, 11 ° 57.43 9 E), grotto wall, from among Bryozoa colonies, 3.5 m depth, 21 June 2003, three specimens ( ZSRO-P1651 ) ; Svalbard, Spitsbergen , Kongsfjorden , BlomstrandhalvØya , marine grotto near Hansneset (78 ° 59.08 9 N, 11 ° 57.43 9 E), grotto wall, from among Bryozoa colonies, 4 m depth, 21 June 2003, 13 specimens ( ZSRO-P1652 ) .

Description

Holotype complete with 35 chaetigers, total length 3.3 mm, width 0.4 mm. Paratypes between 0.8 and 4.1 mm long and 0.37 and 0.54 mm wide, with 18–35 chaetigers. Prostomium with frontal horns anteriorly, with four eyes trapeziformly arranged with posterior pair smaller and usually more closely spaced ( Figures 1A, 2A ); occipital antenna absent; prostomium terminating posteriorly in a small caruncle extending to the middle/ end of chaetiger 1; palps relatively short, extending at most to chaetiger 10 in preserved specimens. Very small nuchal organ as ciliated patches at the posterior margin of the prostomium ( Figures 1A, 2A ). Body not distinctly divided in different regions, with transversal ciliated crests dorsally and smooth surface ventrally ( Figure 2B ). Mid-segmental ciliated crest from chaetiger 2 to about chaetiger 10, thereafter ciliated crest at the posterior margin of chaetigers. Branchiae completely absent. Lateral organs absent. Postchaetal lamellae present; on chaetiger 1 tongue-like ( Figure 1B); thereafter, notopodial lamella first triangular, later broadly rounded ( Figure 1C–E), absent posteriorly; neuropodial lamella broadly rounded, absent when hooks appear ( Figure 1C–E). Notopodia with smooth or hirsute capillaries, usually in two rows. Anterior neuropodia with smooth or hirsute capillaries, from chaetiger 8 or 9 in juveniles and from chaetiger 11 or 12 in adults additionally one or two hooded hooks ( Figures 1H, 2E ), usually only slightly bent, uni- or bidentate ( Figure 1H); with appearance of hooks, the number of capillaries decreases considerably, one or two capillaries up to chaetiger 14 at most, in posterior chaetigers two or three neuropodial hooded hooks, uni-, bi- or sometimes tridentate ( Figure 2F ); spines, with longitudinal groove basally ( Figures 1F, G, 2C, D ) first appear on chaetiger 14 on specimens with more than 28 chaetigers in total (one specimen with 33 chaetigers without spines as an exception), only one grooved spine per neuropodium present, grooved spines replace hooded hooks from chaetiger 14 up to chaetiger 20, depending on total number of chaetigers ( Table I), sometimes on posteriormost spine-bearing neuropodia one hooded hook present additionally; spines are 10–12 mm in diameter at the very base, posterior spines sometimes thinner; grooved spines associated with glandular organs ( Figures 1F, 2C , 3B ). Glandular organs about 25–35 mm in diameter ( Figure 3A, B ). Sabre chaetae (recurved chaetae with a broad blade in the ventralmost position of the neuropodia) absent. Pygidium with four anal lobes, maximum about 58 mm in length. No discernible methyl green or Shirlastain A ẹ staining pattern.

Additional observations

The hooded hooks and spines are sometimes asymmetrically arranged. For example, hooded hooks are first present only on one side of the body, whereas the corresponding neuropodium of the other side still bears capillaries. In other cases, spines may be developed in some neuropodia, whereas hooded hooks are present on the corresponding neuropodia of the other side.

Etymology

The species is dedicated to Dr Jürgen Laudien of the Alfred-Wegener-Institut Bremerhaven. He collected some of the specimens and he assisted us greatly during our field investigations on Spitsbergen in June 2003.

Geographical distribution

Species known only from the type locality.

Figures

Figure 2. Glyphochaeta laudieni gen sp. n., SEM micrographs. (A) Anterior end, frontal view; (B) anterior end, ventral view; (C) lateral view of chaetigers 12–15, neuropodial hooded hooks of chaetiger 12 and 13 broken off; (D) grooved spine of chaetiger 16; (E) neuropodial hooded hooks of a posterior chaetiger; (F) neuropodial hooded hook of a posterior chaetiger, two apical teeth above the main tooth. Scale bars: 60 mm (A, C); 100 mm (B); 10 mm (D); 4 mm (E); 3 mm (F).

Figure 3. Glyphochaeta laudieni gen sp. n., light micrographs. (A) Sagittal section through chaetiger 14 and 15 with glandular organ in chaetiger 14 and grooved spine in chaetiger 15; (B) sagittal section through chaetiger 14 with glandular organ associated with grooved spine. Scale bars: 30 mm. coe, coelom; g, gut; gl, glandular organ; sp, grooved spine.