Kirkegaardia serratiseta ( Banse & Hobson, 1968 ) Banse & Hobson, 1968

Blake, James A., 2016, Kirkegaardia (Polychaeta, Cirratulidae), new name for Monticellina Laubier, preoccupied in the Rhabdocoela, together with new records and descriptions of eight previously known and sixteen new species from the Atlantic, Pacific, and Southern Oceans, Zootaxa 4166 (1), pp. 1-93 : 35-36

Kirkegaardia serratiseta ( Banse & Hobson, 1968) new combination

Figure 16

Tharyx serratisetis Banse & Hobson, 1968: 39 –40, Fig. 7 k–l; Hobson & Banse 1981: 553, Fig. 9 m. Aphelochaeta serratiseta: Blake 1991: 28 .

Monticellina serratiseta: Blake 1996: 325 –324, Fig. 8.25; Welch & Dutch 2014: 5 –7, 8 figs. Not Monticellina cf. serratiseta: Diaz-Diaz et al. 2014: 357 –358, Fig. 2 f–i.

Material Examined. Northeastern Pacific , Puget Sound, East Anderson Island, Sta. 44, Rep. 1, 0 7 April 1992, 47.16133°N, 122.67358°W, 20 m, 3 specimens ( MSMP AN 295 ) ; Shoreline Elliott Bay , Sta. 181, Rep. 1, 18 June 1998, 47.61504°N, 122.36230°W, 36.7 m, 2 specimens ( MSMP AN 1084 ) ; Magnolia Bluff , Sta. 32, Rep. 5, 25 March 1990, 47.63192°N, 122.40850°W, 21 m, 1 specimen ( MSMP AN 2345 ) .

Description. A large species, complete specimen from Sta. 181, 40 mm long, 1.8 mm wide across thorax with about 300 setigerous segments; all segments narrow, crowded. Thoracic region with about 50 setigers, gradually transitioning into abdominal segments; these also narrow and crowded ( Fig. 16 A–B). Noto- and neuropodia closely spaced, located in raised mounds extending as shoulders along body ( Fig. 16 A); in cross section, thoracic region high, rounded dorsally well above parapodia, flattened, slightly concave ventrally with distinct ventral groove; middle and posterior segments with deep ventral groove with parapodial shoulders shifting ventrally, forming sides of groove ( Fig. 16 C). Far posterior end gradually narrowing with pygidium consisting of a simple ventral lobe below anal opening ( Fig. 16 C). Color in alcohol light tan to brown; posterior thoracic segments sometimes appearing creamy in color but not glandular as with some species of Aphelochaeta .

Prostomium triangular to conical, pointed on anterior margin ( Fig. 16 A–B); eyes lacking; nuchal organs curved grooves on posterior border; prostomium and peristomium together slightly longer than wide ( Fig. 16 A–B); peristomium typically with three annular rings ( Fig. 16 A–B); dorsal tentacles medial, arising at level of setiger 1 on posterior medial extension of peristomium. First pair of branchiae arising lateral to dorsal tentacles on anterior margin of setiger 1; second branchiae on posterior margin of setiger 1 dorsal to notosetae; subsequent branchiae in same position on setiger 2 and following setigers.

Parapodia well developed anteriorly, produced into expanded tori bearing dense fascicles of 25 or more long, smooth, silky capillary setae ( Fig. 16 B); middle segments similar, with long, smooth notosetae and shorter, broad, distinctly serrated or denticulated neurosetae ( Fig. 16 D); posterior setae short, reduced to 5–8 per fascicle; denticulated notosetae absent; serrated neurosetae not apparent on last few setigers; denticulated neurosetae with numerous tightly spaced denticles along one edge; denticles apparent only at 1000x ( Fig. 16 D).

Methyl Green stain. Stain not retained anywhere on the body after differentiation.

Remarks. Kirkegaardia serratiseta is an unusual species; with its large robust size, morphology of the presetigerous region, and numerous crowded segments with dense fascicles of long, silky capillaries, it superficially resembles species of Aphelochaeta rather than Kirkegaardia. Indeed, the only character allying the species to Kirkegaardia is the denticulated or serrated neurosetae.

The record of M. cf. serratiseta by Diaz-Diaz et al. (2014) from Venezuela is of a different species because the prostomium is longer than wide and lacks any annulations ( Diaz-Diaz et al. 2014: Fig. 2 f) despite the text stating there are three; in addition, the pygidium is of a different morphology.

Biology. Kirkegaardia serratiseta occurs in sediments consisting mostly of sand and lesser amounts of silt and clay ( Banse & Hobson 1968). Blake (1996) reported one specimen with eggs measuring 110 x 150 µm.

Distribution. Known only from the Puget Sound in sandy sediments, 9– 84 m.

Figures

FIGURE 2. Kirkegaardia heterochaeta (Laubier, 1961), photomicrographs of specimens from Golfe de Fos showing Methyl Green staining pattern in different views: A, left dorsolateral view; B, right lateral view; C, ventral view; D, left lateral view. (MCZ 35295)

FIGURE 7. Kirkegaardia baptisteae (Blake, 1991): A, anterior end, dorsal view; B, anterior end in right lateral view; C, posterior end, dorsal view; D, abdominal notosetae; E, abdominal neuroseta. (USNM 1407152).

FIGURE 9. Kirkegaardia carolina n. sp.: A, anterior end, dorsal view; B, posterior abdominal segments, lateral view, dorsal side to the right; C, posterior end, left lateral view; D, abdominal denticulated neurosetae. (USNM 1407162).

FIGURE 16. Kirkegaardia serratiseta (Banse & Hobson, 1968), specimens from Puget Sound: A, anterior end, right lateral view; B, anterior end, right ventrolateral view; C, posterior end, ventrolateral view; D, denticulated neuroseta. A – B, stained with Shirlastain A. A – B (MSMP AN 295); C – D (MSMP AN 1084).