Kirkegaardia dutchae, Blake, James A., 2016

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 : 38-42

Kirkegaardia dutchae new species

Figures 18–19

Monticellina sp. N 1. Welch & Dutch 2014: 9, 4 figs; Washington State Department of Ecology MSMP; database online: (PSEmpMarineBenthicSpeciesList_sortable.xlsx) online: http://www.eopugetsound.org/species/custom-lists/306. Monticellina tesselata: Welch & Dutch 2014: 7 –8, 6 figs. Not Hartman 1960.

Material examined. Northeastern Pacific, Puget Sound, Shoreline Elliott Bay , Sta. 181, Rep. 1, 18 June 1998, 47.61504°N, 122.36230°W, 36.7 m, coll . MSMP, 4 paratypes (LACM-AHF Poly 8930); Sta. 182, Rep. 1, 18 June 1998, 47.60421°N, 122.34413°W, 38.3 m, coll. MSMP, holotype and 4 paratypes (LACM-AHF Poly 8931–2); Mid Elliott Bay , Sta. 189, Rep. 1, 22 June 1998, 47.59051°N, 122.38049°W, 14.3 m, coll . MSMP, 2 paratypes (LACM-AHF Poly 8933); Port Gamble Bay , Sta. 213, Rep. 1, 25 June 1999, 47.82230°N, 122.57560°W, 4.7 m, 2 specimens ( MSMP AN 1542 ) ; Freshwater Bat, Sta. WA 1007, Rep. 1, 27 Aug. 1999, 48.14972oN, 123.602500W, 21.6 m, 1 specimen (MSMP AN 2 163); Port Orchard, St. Clair inlet, Sta. 202, Rep. 1, 12 June 2009, 47.56099°N, 122.59580°W, 3.9 m, 2 specimens ( MSMP AN 1957 ).— Olympic Coast National Marine Sanctuary , Washington Coastal EMAP Sta. 3-114, Rep. 1, 0 3 June 2003, 47.62012°N, 124.75491°W, 82.0 m, (1 long, thin paratype in 2 parts) (LACM-AHF Poly 8934).

Description. A slender, elongate, and threadlike species; holotype complete, 14 mm long, 0.30 mm wide across thoracic region, 0.25 mm wide across abdominal segments, with 82 setigerous segments. Thoracic region relatively narrow, with 12–14 setigerous segments ( Figs. 18 A, 19A, D–E); parapodia only slightly elevated forming lateral shoulders, with dorsum broad and higher than parapodia ( Fig. 18 A) domed, rounded in cross section. Venter of thoracic region broadly flattened, middle and posterior thoracic segments with distinct glands that appear lighter than rest of body and stain darkly with MG ( Fig. 19 A–B). Thoracic segments narrow, about 4.5x as wide as long, transitioning to weakly moniliform anterior abdominal segments, only 0.3x as wide as long ( Fig. 18 B); middle abdominal segments as long as wide, more of a block shape than oval ( Fig. 18 C); far posterior segments again becoming narrow, forming weakly expanded posterior end with up to 15 setigerous segments and weak ventral groove, terminating in narrow pygidium with terminal anus and a single conical ventral lobe ( Figs. 18 D, 19E).

Prostomium conical, tapering to rounded anterior end ( Figs. 18 A–B, 19C–D); eyes absent; nuchal organs narrow lateral slits at junction with peristomium ( Fig. 18 B). Entire pre-setigerous region elongate, narrow, 2.1x as long as wide in dorsal view, 1.5x as long as wide in lateral view; as long as first six thoracic segments ( Figs. 18 A, 19D). Peristomium either entirely smooth or with 1–2 lateral grooves producing 0–3 partial annular rings ( Figs. 18 A–B, 19C); dorsal surface with low irregular ridge extending over level of setiger 1 and merging with mid-dorsal thoracic surface. Dorsal tentacles arising from posterior margin of peristomium lateral to mid-dorsal ridge ( Fig. 18 A); first pair of branchiae on anterior border of setiger 1; lateral to dorsal tentacles; second pair of branchiae on posterior border of setiger 1, thus two branchiae on setiger 1 ( Figs. 18 A, 19C); following thoracic branchiae on posterior border of each setiger.

Parapodia shifted dorsally in thoracic segments forming distinct lateral shoulders below broadly rounded dorsal surface ( Fig. 18 A); abdominal parapodia located laterally. Individual noto- and neuropodia generally close together along body, each with low podial lobes from which setae emerge ( Fig. 18 E). Notosetae all simple, smooth capillaries throughout with fibrils and serrations not evident with light microscopy; thoracic and anterior abdominal neurosetae similar to notosetae, transitioning to shorter, broader capillaries in middle abdominal segments at about setigers 35–40; these bearing fine denticles along expanded medial margin ( Fig. 18 E, H–I); some transitional neurosetae of anterior abdominal segments narrow, but with a few longer denticles mid-way along shaft ( Fig. 18 F–G).

Methyl Green stain. Distinct transverse segmental bands across venter of thorax ( Fig. 19 A–B), deepest stain on 3–4 posteriormost thoracic segments; lateral intersegmental vertical bands or patches on anterior abdominal segments ( Fig. 19 A–B); stain not concentrated elsewhere on the body. The ventral thoracic bands correspond to the lighter colored glandular ventral surface of non-stained specimens.

Etymology. This species is named for Ms. Margaret (Maggie) Dutch, Manager of the State of Washington Puget Sound Benthic Monitoring Program and a former colleague; she provided specimens of this species and others from the MSMP reference collections.

Remarks. Kirkegaardia dutchae n. sp. from the northeastern Pacific is most closely related to K. baptisteae from along the U.S. Atlantic shelf and slope in having a similar size and shape to the pre-setigerous region, parapodia limited to lateral shoulders situated lower than the broad dorsal surface, and prominent glands along the venter of thoracic segments.

The two species differ in that K. baptisteae has ventral thoracic glands that are naturally light tan in color and do not produce a MG staining pattern of any kind, with the stain disappearing entirely in clean alcohol; however, these glands may retain pink coloration from Rose Bengal for a time after storage. In contrast, the same glands of K. dutchae n. sp. retain a distinct MG pattern on the venter of the thoracic region after differentiation. Additional differences include denticulated capillaries limited to neuropodia in K. dutchae n. sp. instead of both noto- and neuropodia as in K. baptisteae . Further, the denticles are limited to an expanded knob on the shaft of K. dutchae n. sp. whereas in K. baptisteae the denticles are distributed along most of the shaft. Additionally, the first and second pair of branchiae are on setiger 1 in K. dutchae n. sp.; whereas in K. baptisteae the first pair of branchiae are lateral to the dorsal tentacles on the posterior margin of the peristomium and only the second pair are on setiger 1. K. dutchae n. sp. is also similar to K. tesselata , but differs in lacking a mid-thoracic ridge. All three species, however, are now known to have tessellated tubes.

Biology. Two paratypes from Station 181, June 1998, had numerous sperm packets in the coelom; one paratype from Sta. 182 also collected in June 1998 was packed with yolky eggs having a visible germinal vesicle and measuring 96–127 µm; a paratype from Sta. 189, also collected in June 1998, had both small oocytes ca. 20-µm diameter and larger ova 93–101 µm diameter in adjacent segments. These data suggest that gametes were not fully mature in June; it is likely spawning and recruitment occur later in the summer. The specimens from Sta. 213 were labeled Monticellina tesselata in the MSMP voucher collection because of the surrounding tessellated tube. However, the two specimens agree well with Kirkegaardia dutchae n. sp. and not K. tesselata because a peristomial ridge is present and a mid-thoracic ridge is absent instead of absent and present, respectively, as in K. tesselata ( Blake 1996) . Kirkegaardia dutchae n. sp. is herein recognized as one of several closely related species having the tattered or tessellated tubes first reported for K. tesselata , a California species.

Distribution. Known only from the Puget Sound in shallow depths, 14– 82 m.

Figures

FIGURE 18. Kirkegaardia dutchae n. sp.: A, anterior end, dorsal view; B, anterior end, right lateral view; C, middle abdominal segments, left lateral view, anterior end toward the left; D, posterior end, right lateral view; E, anterior abdominal parapodium, anterior view; F – G, denticulate neurosetae from anterior abdominal segment; H – I, denticulate neurosetae from middle abdominal segment. A, B – I, paratypes (LACM-AHF Poly 8930); B, holotype (LACM-AHF Poly 8931).

FIGURE 19. Kirkegaardia dutchae n. sp.: A – B, two paratypes from Sta. 182 (LACM-AHF Poly 8932) showing Methyl Green staining patterns; A, ventral view; B, right lateral view. — C – E, specimens from Sta. 202 (MSMP AN 1957), stained with Shirlastain A: C, anterior end dorsal view; D, anterior end, left lateral view; E, posterior end, right lateral view.