Kirkegaardia heterochaeta ( Laubier, 1961 )

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: 7-8

publication ID

http://doi.org/10.11646/zootaxa.4166.1.1

publication LSID

lsid:zoobank.org:pub:A4410AB2-6624-48A2-81D2-4746C24189D7

DOI

http://doi.org/10.5281/zenodo.5612204

persistent identifier

http://treatment.plazi.org/id/277D879E-2E74-8947-05E1-2F31FCEA2BC0

treatment provided by

Plazi

scientific name

Kirkegaardia heterochaeta ( Laubier, 1961 )
status

new combination

Kirkegaardia heterochaeta ( Laubier, 1961)   , new combination

Figures 1–2 View FIGURE 1 View FIGURE 2

Monticellina heterochaeta Laubier, 1961: 601   –604; Çinar 2005: 150; Ergen et al. 2006: 201; Çinar et al. 2014: 748. Tharyx heterochaeta: Laubier 1966: 631   –638; Salen-Picard 1981: 83 –88; Nicolaidou et al. 1989: 29; Salen-Picard et al. 1996: 304 –305.

Monticellina dorsobranchialis: Blake 1991: 24   –26 (In part). Not Kirkegaard (1959). Monticellina   cfr. heterochaeta: Dorgham et al. 2014: 640   .

Material examined. Mediterranean Sea , France, Golfe de Fos, west of Marseille, Sta. B, 35 m, coll. C. Salen- Picard, 1979, 10 specimens, donated by L. Laubier ( MCZ 135295 View Materials )   ; same location, Sta. B, 35 m, 7 specimens ( MCZ 135296 View Materials )   ; same location, 42 m 1 specimen ( MCZ 135294 View Materials )   .

Description. Body elongate, thin throughout with thoracic region only weakly expanded and posteriormost segments slightly enlarged. Longest specimens examined 13 mm long, reported up to 35 mm by Laubier (1966); body narrow, 0.3–0.4 mm wide on specimens examined (0.1–0.4 mm wide reported by Laubier 1966) with 50–70 setigers (30–100 reported by Laubier 1966). Body generally colorless in alcohol.

Thoracic setigers each about 5.5x as wide as long for first 12–15 setigers with parapodia shifted dorsally and elevated above mid-dorsal surface forming distinct mid-dorsal groove on thoracic segments ( Fig. 1 View FIGURE 1 A); dorsal surface elevated, forming a distinct ridge line inside mid-dorsal groove ( Fig. 1 View FIGURE 1 A). Ventral surface without grooves or ridges. Abdominal segments becoming longer and narrower, and with parapodia in lateral locations ( Fig. 1 View FIGURE 1 C). Most abdominal segments up to 2x as long as wide ( Fig. 1 View FIGURE 1 C), becoming narrower again in expanded posterior most segments ( Fig. 1 View FIGURE 1 D). Far posterior segments expanded bearing a large rounded pygidium ( Fig. 1 View FIGURE 1 D).

Pre-setigerous area or head region (prostomium + peristomium) very elongate, narrow, about 2.2x long as wide and same length as first 5–6 following setigerous segments ( Fig. 1 View FIGURE 1 A–B). Prostomium short, triangular, bluntly rounded on anterior margin ( Fig. 1 View FIGURE 1 A–B); eyes absent; nuchal organs not observed. Peristomium very elongate, relatively smooth with a single lateral groove in some specimens producing two annular rings ( Fig. 1 View FIGURE 1 A–B); or no rings apparent. Narrow dorsal ridge extends from prostomium about half way along dorsal peristomial mid-line ( Fig. 1 View FIGURE 1 A–B). Paired dorsal tentacles located close together, arising from posterior margin of peristomium ( Figs. 1 View FIGURE 1 A–B); first pair of branchiae posterolateral to dorsal tentacles at boundary with setiger 1, generally in line with subsequent thoracic branchiae located dorsal to notopodia ( Fig. 1 View FIGURE 1 A–B). Segmental branchiae of thoracic region on curved edge of each segment, somewhat projecting into mid-dorsal grove. Most branchiae broken, leaving stubs, best seen in thoracic segments and when stained with Shirlastain A; branchiae continue in mid-dorsal location for as long as observed; branchiae rarely observed in abdominal segments.

Parapodia low mounds with noto- and neuropodia closely spaced ( Fig. 1 View FIGURE 1 E). Thoracic parapodia shifted dorsally; abdominal parapodia more lateral.

Setae all smooth capillaries through thoracic region, numbering about 10–12 in notopodia and same in neuropodia, transitioning to denticulate capillaries in anterior abdominal segments with numbers of setae per fascicle reduced to 6–10. Denticulate setae appear in noto- and neuropodia of anterior abdominal segments from about setigers 11–19 depending on size of worm, appearing more anteriorly on smaller specimens. Denticulate setae with broad shaft and short, curved, downwardly directed denticles along one edge ( Fig. 1 View FIGURE 1 F–G); notosetae ( Fig. 1 View FIGURE 1 G) longer and narrower than neurosetae ( Fig. 1 View FIGURE 1 F); denticulated edge directed ventrally in notosetae and dorsally in neurosetae, thus vis-à-vis ( Fig.1 View FIGURE 1 E).

Methyl Green stain. A distinctive and intense MG staining pattern evident ( Fig. 2 View FIGURE 2 A–D). Stained oval green patch on dorsum of second half of peristomium anterior to origin of dorsal tentacles, extending only weakly down lateral sides of peristomium ( Fig. 2 View FIGURE 2 A, C); no stain on prostomium. Strong staining reaction in thoracic segments, with middle and posterior thoracic segments darkly blue, forming broad bands or stripes extending from middorsum down sides around venter and up opposite side; stain very intense from about setiger 3 to end of thoracic region, weaker on 2–3 segments on either end ( Fig. 2 View FIGURE 2 A–D); abdominal segments with mid-ventral spot or longitudinal line on individual segments ( Fig. 2 View FIGURE 2 B–C); thin lines of stain also present intersegmentally in abdominal segments.

Remarks. The body of Kirkegaardia heterochaeta   is elongate and very slender, with only a minimal expansion of the thoracic region. The species belongs to a group of species with: (1) an elongate prostomialperistomial region that is relative smooth and weakly divided by annular rings and, (2) dorsally elevated thoracic parapodia that overlie the dorsal surface producing a conspicuous dorsal thoracic groove that contains a mid-dorsal ridge. Laubier (1966) observed superficial lines on K. heterochaeta   when studied with sagittal thin sections, suggesting that two annular rings were present. However, even with Shirlastain A, annular rings are difficult to detect externally.

Kirkegaardia heterochaeta   from shallow-water Mediterranean sediments is morphologically most similar to K. brigitteae   n. sp. from deep-sea habitats in Antarctica and the Southern Ocean. The two species have a distinct middorsal peristomial ridge that extends from the prostomium to about halfway along the peristomium, leaving the rest of the dorsal peristomial surface smooth. Both species also have a mid-dorsal thoracic ridge and similar MG staining patterns. The two species differ in that in K. heterochaeta   the mid-dorsal thoracic ridge encompasses the entire dorsal surface of the channel, whereas in K. brigitteae   n. sp. there is a separate and narrow ridge on the surface within the channel. Further, the peristomium of K. heterochaeta   has at least one lateral groove producing two annular rings, whereas K. brigitteae   n. sp. has a smooth peristomium not interrupted by annular rings. The far posterior pre-pygidial segments of K. brigitteae   n. sp. include about 15 segments that are greatly expanded, whereas the same segments of K. heterochaeta   , although also expanded, are few in number, usually no more than three. The MG staining reactions are basically similar in having the venter of the thorax retaining stain; however, K. heterochaeta   has an intensely Green stained patch on the dorsal surface of the peristomium, whereas K. brigitteae   n. sp. has only a weak staining reaction that de-stains rapidly. Ten other species features with K. heterochaeta   ; these are compared in the Discussion section of this paper and detailed in Tables 1 and 2.

Biology. Kirkegaardia heterochaeta   is a relatively common species along the Mediterranean coasts from France to Greece in muddy to muddy-sand sediments and is also reported from the Egyptian coast. Egg diameters of 200–225 µm were recorded for this species by Petersen (1999) from specimens collected in July from the Levantine Basin, eastern Mediterranean, in 65 m by M.E. Çinar. These large eggs suggest that development is direct for this species.

Distribution. Mediterranean Sea, shallow subtidal.

MCZ

Museum of Comparative Zoology

Kingdom

Animalia

Phylum

Annelida

Class

Polychaeta

Order

Terebellida

Family

Ctenodrilidae

Genus

Kirkegaardia

Loc

Kirkegaardia heterochaeta ( Laubier, 1961 )

Blake, James A. 2016
2016
Loc

Monticellina dorsobranchialis:

Dorgham 2014: 640
Blake 1991: 24
1991
Loc

Monticellina heterochaeta

Cinar 2014: 748
Ergen 2006: 201
Cinar 2005: 150
Salen-Picard 1996: 304
Nicolaidou 1989: 29
Salen-Picard 1981: 83
Laubier 1966: 631
Laubier 1961: 601
1961