Dysponetus antarcticus Darbyshire & Brewin, 2015, n. sp.
Dysponetus antarcticus n. sp. Figure 3 A–D 1993: Dysponetus bulbosus Hartmann-Schröder: p 128 – 9. Material examined. South of King George Island, Antarctica, Sta. near O’Higgins (63 ° 00.49′S, 057° 09.45′W), very fine sand with Bryozoa, gorgonians, much detritus, 97 m, holotype (ZMH P- 21914) parat...
| Main Authors: | , |
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| Format: | Other/Unknown Material |
| Language: | unknown |
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2015
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| Online Access: | https://zenodo.org/record/6112766 https://doi.org/10.5281/zenodo.6112766 |
| Summary: | Dysponetus antarcticus n. sp. Figure 3 A–D 1993: Dysponetus bulbosus Hartmann-Schröder: p 128 – 9. Material examined. South of King George Island, Antarctica, Sta. near O’Higgins (63 ° 00.49′S, 057° 09.45′W), very fine sand with Bryozoa, gorgonians, much detritus, 97 m, holotype (ZMH P- 21914) paratype (ZMH P- 27740), 22.12. 1991. Description. Holotype posteriorly incomplete, 2.7 mm long for 15 chaetigers (15 th chaetiger removed for SEM). Paratype whole, juvenile, 1.29 mm for 14 chaetigers. Maximum width measured both between segments, 0.7 mm (holotype) and 0.26 mm (paratype), and including chaetae, 3.0 mm (holotype) and 1.07 mm (paratype). Description based on holotype except where specified. Measurements and counts of chaetae and cirri from holotype only. Body shape cylindrical, ventrally flattened, tapered over last 2–3 segments at posterior. Colour pink-brown in alcohol. Prostomium sub-rectangular (Fig. 3 A), only slightly wider anteriorly. Eyes absent or degraded beyond visibility (see Remarks for comment on presence of eyes). Median antenna, present on paratype but not holotype, anterodorsally attached, same shape but slightly shorter than lateral antennae. Lateral antennae bottle-shaped (Fig. 3 B), 1 remaining on holotype (150 µm long), arising immediately dorsal to palps. Palps (190 µm long) directed posteriorly (Fig. 3 B), stouter than antennae or cirri, approximately 3 times as long as wide. Nuchal organs not observed. Single mouth appendage small, difficult to discern. Single pair of small jaws, barely visible through body even with methyl green staining. Proboscis not observed. First two segments elevated dorsally with four pairs tentacular cirri, dorsal pairs lost, ventral pairs of similar shape and size as following ventral cirri. First segment achaetous, second segment with notochaetae only, situated anterior to dorsal tentacular cirrus, easily confused with first segment. Third and following segments all biramous, dorsal, ventral cirri, noto- and neurochaetae present. Cirrophores present. ... |
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