Capitellethus cinctus Thomassin, 1970

Magalhães, Wagner F. & Bailey-Brock, Julie H., 2012, Capitellidae Grube, 1862 (Annelida: Polychaeta) from the Hawaiian Islands with description of two new species, Zootaxa 3581, pp. 1-52 : 19-23

publication ID

https://doi.org/ 10.5281/zenodo.215310

publication LSID

lsid:zoobank.org:pub:07C06068-9160-4AB4-AAF4-0451679D9F13

DOI

https://doi.org/10.5281/zenodo.6175606

persistent identifier

https://treatment.plazi.org/id/03913362-FF9D-FF9F-99BE-FB409B634C8D

treatment provided by

Plazi

scientific name

Capitellethus cinctus Thomassin, 1970
status

 

Capitellethus cinctus Thomassin, 1970 View in CoL

Figures 13 View FIGURE 13 A–C, 14 A–F, 15 A–D

Capitellethus cinctus Thomassin, 1970: 77 View in CoL –79, fig. 4.

Capitellethus cinctus View in CoL .— Green 2002: 278 –280, fig. 9a–i.

Material examined. Oahu Island: Mamala Bay, Sand Island outfall, Sta. E6R2, 2115ʹ50.8ʺ N, 15750ʹ57.9ʺ W, 102.1 m, Aug. 2000 (1, BPBM R3599); Sta. E2R3, 2116ʹ43.4ʺ N, 15754ʹ39.1ʺ W, 101.2 m, Aug. 2007 (1); Sta. E3R1, 2116ʹ44.0ʺ N, 15753ʹ49.4ʺ W, 82.6 m, Aug. 2000 (1); Sta. D2R2, 2116ʹ56.5ʺ N, 15754ʹ35.0ʺ W, 53.3 m, Aug. 2000 (3, BPBM R3600); Sta. D1R1, 2117ʹ23.4ʺ N, 15755ʹ30.1ʺ W, 48.8 m, Aug. 2000 (1); Sta. D2R2, 2116ʹ56.5ʺ N, 15754ʹ35.0ʺ W, 53.3 m, Aug. 2002 (1); Mamala Bay, Barbers Point outfall, Sta. HB1R5, 2116ʹ51.0ʺ N, 15759ʹ20.2ʺ W, 64.9 m, Mar. 2000 (1); Sta. HZR4, 2116ʹ53.1ʺ N, 15801ʹ30.3ʺ W, 62.5 m, Mar. 2000 (1); Sta. HB2R4, 2117ʹ0 0.5ʺ N, 15801ʹ21.2ʺ W, 59.1 m, Mar. 2000 (1); Sta. HB6R1, 2116ʹ33.1ʺ N, 15801ʹ48.1ʺ W, 59.4 m, Mar. 2000 (2); Sta. HB2R1, 2117ʹ0 0.5ʺ N, 15801ʹ21.1ʺ W, 58.8 m, Mar. 2000 (2); Sta. HB7R1, 2115ʹ30.5ʺ N, 15803ʹ11.4ʺ W, 65.2 m, Mar. 2000 (3, BPBM R3603); Sta. HB4R4, 2116ʹ47.1ʺ N, 15801ʹ38.0ʺ W, 63.4 m, Mar. 2000 (1); Sta. HB7R4, 2115ʹ30.2ʺ N, 15803ʹ11.4ʺ W, 65.2 m, Mar. 2000 (2, BPBM R3601); Sta. HB2R5, 2117ʹ0 0.4ʺ N, 15801ʹ21.5ʺ W, 59.4 m, Mar. 2001 (1); Sta. HB2R2, 2117ʹ0 0.1ʺ N, 15801ʹ21.3ʺ W, 60.0 m, Mar. 2001 (1, BPBM R3602); Sta. HB7R3, 2115ʹ30.4ʺ N, 15803ʹ11.6ʺ W, 66.4 m, Mar. 2001 (1); Sta. HZR1, 2116ʹ54.0ʺ N, 15801ʹ30.3ʺ W, 62.5 m, Mar. 2004 (1); Sta. HB2R2, 2117ʹ0 0.1ʺ N, 15801ʹ21.3ʺ W, 60.0 m, Mar. 2002 (1); Sta. HB2R1, 2117ʹ0 0.5ʺ N, 15801ʹ21.1ʺ W, 58.8 m, Mar. 2002 (1); Sta. HB6R3, 2116ʹ33.3ʺ N, 15801ʹ48.3ʺ W, 59.4 m, Feb. 2006 (1). Waianae outfall, Sta. ZWR4, 2125ʹ25.1ʺ N, 15811ʹ55.4ʺ W, 34 m, May 2001 (1); Sta. ZWR1, 2125ʹ25.1ʺ N, 15811ʹ55.4ʺ W, 34 m, May 2001 (1); Sta. W9R2, 2126ʹ29.4ʺ N, 15812ʹ16.3ʺ W, 33 m, May 2002 (1); Sta. ZR4, 2125ʹ22.9ʺ N, 15811ʹ51.1ʺ W, 35 m, May 2002 (1); Sta. W9R2, 2126ʹ29.4ʺ N, 15812ʹ16.3ʺ W, 34 m, May 2007 (1); Sta. W1R2, 2123ʹ32.5ʺ N, 15811ʹ27.7ʺ W, 31 m, Jun. 2011 (1). Maui Island: Kahekili Beach Park, collected on Halimeda kanaloana meadows, 30 m, Jun. 2005, coll. A. Fukunaga (1).

Description. Complete specimens 7–35 mm long, 0.1–0.5 mm wide for 74–180 chaetigers. Body elongate, slender, tapering from abdominal segments to pygidium; rounded in cross section. Color in alcohol pale yellow with both annuli of chaetiger 11 and anterior annulus of chaetiger 12 covered by glands staining dark brown and forming complete rings ( Fig. 15 View FIGURE 15 C, D).

Prostomium conical with digitate palpode ( Figs 13 View FIGURE 13 A, 14A); sometimes partially retracted. Nuchal organs not observed. Eyespots 10–14 on either side, in two irregular rows ( Fig. 13 View FIGURE 13 A). Everted proboscis with papillae on distal end ( Figs 13 View FIGURE 13 A, 14A). Peristomium achaetous; as long as chaetiger 1 ( Figs 13 View FIGURE 13 A, 14A).

Thorax with 11 chaetigers; chaetiger 1 with notochaetae only and parapodia reduced throughout ( Figs 13 View FIGURE 13 , 14 View FIGURE 14 A). Chaetigers 1–4 slightly inflated dorsally, indistinctly differentiated, chaetigers 5–11 biannulated with deep inter-segmental groove ( Figs 13 View FIGURE 13 A, 14A). Thorax with bilimbate capillaries only, inserted in mid-segment. Lateral organs present on thorax from chaetiger 7–11, not observed on abdominal segments. Genital pores not observed.

Transition between thorax and abdomen marked by dark brown glandular bands and change in chaetae ( Figs 13 View FIGURE 13 A, 15C, D); abdominal chaetigers with hooded hooks throughout. Abdominal noto- and neuropodial hooks more closely spaced than in thoracic fascicles. Abdominal neuropodial lobes not fused ventrally, anterior abdominal segments with 10–12 hooded hooks and posteriorly with 12–14 slightly shorter hooded hooks per fascicle. Notopodial abdominal hooks slightly longer than neuropodial hooks but similar in shape. Hoods short with insertion above widest part of hook’s shoulder ( Fig. 14 View FIGURE 14 D, E). Hooks with multiple teeth, in lateral view with 4–5 teeth above main fang and in frontal view with at least three rows of teeth; two in basal row, three in middle and two in superior row ( Fig. 14 View FIGURE 14 D–F).

Branchiae retractile, occurring dorsally on far posterior abdominal segments, starting about 20–30 chaetigers before pygidium in large specimens ( Figs 13 View FIGURE 13 B, C, 14B). Branchial tufts of 2–3 digitate lobes at each side, projecting from lateral end of notopodial lobe ( Fig 13 View FIGURE 13 B, C). Pygidium with four digitate lobes, two dorsal and two ventral ( Figs 13 View FIGURE 13 C, 14C); ventral lobes 1.5 longer than dorsal lobes; terminal anal aperture.

Methyl green staining pattern. Prostomium, peristomium and first 3–4 chaetigers unstained or with very light staining; staining gradually darkens from chaetiger 5 posteriorly to end of thorax ( Fig. 15 View FIGURE 15 A). Abdominal chaetigers, except chaetiger 12, which stains similarly to the last thoracic chaetiger, with pre- and post-chaetal dark bands on noto- and neuropodial tori ( Fig. 15 View FIGURE 15 B).

Distribution. This species was originally described from the southwest coast of Madagascar ( Thomassin 1970) but has been recorded from the Andaman Sea, Thailand ( Green 2002) and it is now newly recorded for Oahu, Hawaii. This species seems to be one of the most abundant and widely distributed capitellids in Oahu and has been erroneously identified as Notomastus tenuis in unpublished reports (see e.g. Ambrose et al. 2010).

Remarks. The specimens from Oahu, Hawaii agree well with earlier descriptions of Capitellethus cinctus by Thomassin (1970) and Green (2002). The dark pigmented bands on the transition between thorax and abdomen are conspicuous in this species and separate it readily from other Hawaiian capitellids. The MGSP for this species was well described by Green (2002) and agrees with the Hawaiian material except that chaetiger 6 is not always darkly stained and the abdominal neuropodial tori are always stained in the Hawaiian material.

The original and subsequent descriptions of this species were based on fragmented specimens and the far posterior abdominal segments and pygidium had not been previously described. Branchial tufts are present on posterior segments and are illustrated herein in line drawings and SEM images. The pygidium is very distinct with four digitate lobes; the anal aperture is terminal.

Capitellethus cinctus View in CoL is distinct from its congeners due to the presence of only capillaries in thoracic chaetigers, chaetiger 1 being uniramous, darkly pigmented glandular bands on chaetigers 11–12, the presence of branchiae, and a distinct MGSP. It is most similar to Capitellethus branchiferus Gallardo, 1968 View in CoL but as pointed out by Green (2002), these species have a distinct MGSP and C. branchiferus View in CoL has hooded hooks in the neuropodium of chaetiger 11.

Kingdom

Animalia

Phylum

Annelida

Class

Polychaeta

Family

Capitellidae

Genus

Capitellethus

Loc

Capitellethus cinctus Thomassin, 1970

Magalhães, Wagner F. & Bailey-Brock, Julie H. 2012
2012
Loc

Capitellethus cinctus

Green 2002: 278
2002
Loc

Capitellethus cinctus

Thomassin 1970: 77
1970
GBIF Dataset (for parent article) Darwin Core Archive (for parent article) View in SIBiLS Plain XML RDF