Chaetozone barentsensis, Grosse & Capa & Bakken, 2021

Grosse, Mael, Capa, Maria & Bakken, Torkild, 2021, Describing the hidden species diversity of Chaetozone (Annelida, Cirratulidae) in the Norwegian Sea using morphological and molecular diagnostics, ZooKeys 1039, pp. 139-176 : 139

publication ID

https://dx.doi.org/10.3897/zookeys.1039.61098

publication LSID

lsid:zoobank.org:pub:F2F861A5-33DF-4B61-827D-EB71AB97E97F

persistent identifier

https://treatment.plazi.org/id/5A4E27EE-59D3-48E9-9F89-2C061FCDDDDF

taxon LSID

lsid:zoobank.org:act:5A4E27EE-59D3-48E9-9F89-2C061FCDDDDF

treatment provided by

ZooKeys by Pensoft

scientific name

Chaetozone barentsensis
status

sp. nov.

Chaetozone barentsensis sp. nov. Figure 8 View Figure 8

Chaetozone sp. 3 Grosse et al. 2020: fig. 4.

Type locality.

Barents Sea, 337 m depth.

Material examined.

Holotype: Barents Sea • 1 ind.; 71.056°N, 29.655667°E; 21 Apr. 2014; 337 m; NTNU-VM74492. Paratypes: Barents Sea • 7 ind.; 71.056°N, 29.655667°E; 21 Apr. 2014; 337 m; NTNU-VM74493-74498, ZMBN129638 • 2 ind.; 71.187833°N, 28.943167°E; 23 Apr. 2014; 380 m; NTNU-VM74489, ZMBN129639. - North Sea • 1 ind.; 60.173°N, 5.003°E; 22 Apr. 2011; 6 m; ZMBN95707 GoogleMaps .

Diagnosis.

Dorsal tentacles on distinct segment 1 (achaetous); first branchiae on indistinct segment 2 (achaetous); approximately 22 short, flat spines per parapodia in posterior segments (Fig. 8 View Figure 8 ).

Molecular diagnosis.

COI: 158: A; 214: G; 518: A; 283-284: CT; 289-290: TA. 28S: 37: A; 419: T; 457: A; 461: A; 462: A; 510: C (based on 13 COI sequences and 3 28S sequences).

Description.

A small species, holotype complete, 40-48 segments, 4-5 mm long, 0.25 mm wide (Fig. 8A View Figure 8 ). Colour in ethanol white to light grey. Body elongate, without any distinct enlargement, rather round in cross section, slightly flattened in posterior half. Anterior segments 4 × higher than long. Posterior segments 2 × higher than long. Dorsal groove over posterior half. Ventral ridge along entire body.

Prostomium as long as peristomium, 2 × longer than high, conical, without annulations; eyespots absent; nuchal organs simple slits at posterior margin of prostomium (Fig. 8B View Figure 8 ). Peristomium short, as long as two anterior segments, sometimes appears partially divided in two annulations, one anterior to mouth and one bearing mouth (Fig. 8B View Figure 8 ). Dorsal tentacle arising from segment 1 (achaetous), well separated. Segment 1 achaetous, distinct from peristomium (Fig. 8B View Figure 8 ). First pair of branchiae arising from segment 2 (achaetous), aligned with dorsal tentacles and second pair of branchiae (Fig. 8B View Figure 8 ). Segment 2 achaetous, often indistinct from segment 1 and chaetiger 1 (Fig. 8B View Figure 8 ). Second pair of branchiae arising from chaetiger 1, dorsal to notopodia (Fig. 8B View Figure 8 ). Subsequent branchiae similarly placed. Branchiae or branchial scars present on most chaetigers until development of cinctures.

Parapodia as low mounds or ridges in anterior and middle parts, progressively developing into elevated membrane and into complete cinctures around segment 25-37 (Fig. 8A View Figure 8 ). Thirteen smooth short capillary chaetae present in all chaetigers 2-4 long chaetae in anterior notopodia, up to several times body width. 22 spines from segment 24-28 in neuropodia and segment 25-29 in notopodia, short, slightly curved, dorsalmost spines thin and rounded in cross section, gradually flattening and widening towards most lateral positions (Fig. 8C View Figure 8 ). Alternating capillaries present between all spines, longer than spines (Fig. 6C View Figure 6 ).

Pygidium with terminal anus and with a small rounded ventral lobe.

Methylene blue staining pattern.

No particular pattern. Prostomium and peristomium retains slightly more stain than rest of body.

Etymology.

The name comes from the Barents Sea, where the species was found.

Remarks.

Chaetozone barentsensis sp. nov. is similar in general appearance to C. setosa , which is found in the same area, although it is smaller (up to 5 mm vs. 3 cm for C. setosa ) and differs, in particular, in the position of its tentacles which arise from the first achaetous segment vs. posterior margin of the peristomium for C. setosa , the presence of a ventral ridge instead of a groove, and the shape of its spines which are significantly shorter than that of C. setosa .

Chaetozone barentsensis sp. nov. COI distance with other species in the area mostly ranges from 23% to 26%, with a minimum of 9% with Chaetozone sp. 14 (Table 2 View Table 2 ).

Distribution.

Chaetozone barentsensis sp. nov. is found in the Barents Sea, ~ 400 m depth. One specimen was found on the Norwegian coast outside Bergen at 6 m depth.

Kingdom

Animalia

Phylum

Mollusca

Class

Polychaeta

Order

Terebellida

Family

Cirratulidae

Genus

Chaetozone

Loc

Chaetozone barentsensis

Grosse, Mael, Capa, Maria & Bakken, Torkild 2021
2021
Loc

Chaetozone

Grosse & Capa & Bakken 2021
2021