Leitoscoloplos rankini, Blake, James A., 2017

Blake, James A., 2017, Polychaeta Orbiniidae from Antarctica, the Southern Ocean, the Abyssal Pacific Ocean, and off South America, Zootaxa 4218 (1), pp. 1-145 : 36-39

publication ID

https://doi.org/ 10.5281/zenodo.245827

publication LSID

lsid:zoobank.org:pub:9345C596-8656-4B5C-AD8C-2FACF4E9240C

DOI

https://doi.org/10.5281/zenodo.4901763

persistent identifier

https://treatment.plazi.org/id/8F2387DD-0636-092B-FF31-F8AEFCA2FA5C

treatment provided by

GgServerImporter

scientific name

Leitoscoloplos rankini
status

sp. nov.

Leitoscoloplos rankini View in CoL new species

Figures 17–18 View FIGURE 17 View FIGURE 18

Haploscoloplos View in CoL sp. Hartman 1978: 156 (in part, Glacier Sta. 69-19).

Material examined. Drake Passage, ANDEEP I ANT XIX-3, R/V Polarstern, Sta. PS-61/43- 2, 3959 m (1, SEM, JAB); Sta. PS-61/46- 3, 2888 m (1, ZMH P-27799).—Weddell Sea, Glacier Sta. 69- 19, 11 Mar 1969, 74.105°S, 32.603°W, 1622 m, holotype (USNM 1013903); ANDEEP III ANT XXII-3, R/V Polarstern, Sta. PS-67/121- 6, 2618 m (1, ZMH P-27800).

Description. Holotype posteriorly incomplete, broken into three parts, 22 mm long, 1 mm wide for 50 setigerous segments; 10 thoracic setigers. Specimen from Sta. PS-61, 46-3 complete, 19 mm long, 0.8 mm wide for 80 setigers; with 11 thoracic setigers. Specimen from Sta. PS-67, 110-11 smaller, complete, in two parts, 7 mm long, 0.4 mm wide for 40 setigers; with 9 thoracic setigers.

Thoracic region widest part of body, with 9–11 setigers, rounded in cross section, not depressed ( Fig. 17 View FIGURE 17 B). Transition between thorax and abdomen abrupt ( Fig. 17 View FIGURE 17 A) or with one transitional segment. Abdominal segments becoming narrow in posterior one-third of body. Branchiae from setiger 18–21, small and stubby at first, becoming thin, about twice as long as notopodial postsetal lobes ( Fig. 17 View FIGURE 17 C).

Prostomium conical, pointed; no eyespots ( Figs. 17 View FIGURE 17 A, 18A); nuchal organs as large slit between prostomium and peristomium ( Fig. 18 View FIGURE 18 B). Peristomium with one achaetous ring ( Figs. 17 View FIGURE 17 A, 18A).

Thoracic segments all similar, with prominent postsetal lobes; notopodial postsetal lobes subtriangular ( Fig. 17 View FIGURE 17 B); neuropodial postsetal lobe arising from low postsetal ridge ( Fig. 17 View FIGURE 17 B). Middle and posterior abdominal parapodia dorsally elevated; elevated parapodia fused across dorsum, forming raised dorsal crest from which branchiae arise, best observed in posterior abdominal segments ( Fig. 18 View FIGURE 18 C). Abdominal notopodia with narrow fingerlike postsetal lobe ( Figs. 17 View FIGURE 17 C, 18D); neuropodia elongated, apically expanded, divided into two lobes between which setae arise ( Fig. 17 View FIGURE 17 C); without subpodial flange.

Branchiae short at first ( Fig. 18 View FIGURE 18 C–D), then becoming longer than notopodial lobes in far posterior segments ( Fig. 17 View FIGURE 17 C).

Thoracic setae all crenulated capillaries ( Fig. 18 View FIGURE 18 E); notopodial fascicles with 6–8 setae; neurosetae more numerous, arranged in two dense rows. Abdominal notopodia with 6–9 long capillaries and 3–4 furcate setae; each furcate seta with one tyne shorter than the other, both blunted on tips with apical notch; tynes connected by thin webbing composed of fine needles ( Fig. 17 View FIGURE 17 D). Abdominal neuropodia with long and short capillaries; 1–2 very short and thin aciculae, sometimes protruding. Pygidium with two thin cirri.

Etymology. This species is named for the late Dr. John S. (Stubby) Rankin, Professor Emeritus of the University of Connecticut, friend, and teacher. Dr. Rankin was director of the sampling program during the International Weddell Sea Expedition (1968–69).

Remarks. Leitoscoloplos rankini n. sp. is a deep-sea species belonging to the L. kerguelensis group in having branchiae first present from the anterior abdominal region. The species differs from related forms in the nature of the inflated and elevated parapodia of the posterior abdominal segments. These parapodia are located on the posterior border of the segments and are elevated dorsally to form prominent crests. Further differences with related forms are discussed under L. eltaninae n. sp. (see above).

Distribution. Drake Passage and Weddell Sea, 1622–3959 m.

Kingdom

Animalia

Phylum

Annelida

Class

Polychaeta

Family

Orbiniidae

Genus

Leitoscoloplos

Loc

Leitoscoloplos rankini

Blake, James A. 2017
2017
Loc

Haploscoloplos

Hartman 1978: 156
1978
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