Chaetozone

Key to 21 species of Chaetozone from the Northeastern Pacific and North American Arctic and Subarctic (Reference code: 1, Blake 1996; 2, Blake 2006; 3, this paper. Note: Chaetozone gracilis Moore, 1923 and C. armata Hartman, 1963, both redescribed in Blake [1996] are rare species not included in thi...

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Bibliographic Details
Main Author: Blake, James A.
Format: Other/Unknown Material
Language:unknown
Published: 2015
Subjects:
Online Access:https://zenodo.org/record/5664954
https://doi.org/10.5281/zenodo.5664954
Description
Summary:Key to 21 species of Chaetozone from the Northeastern Pacific and North American Arctic and Subarctic (Reference code: 1, Blake 1996; 2, Blake 2006; 3, this paper. Note: Chaetozone gracilis Moore, 1923 and C. armata Hartman, 1963, both redescribed in Blake [1996] are rare species not included in this key; both lack posterior cinctures and may belong to other genera. MG = Methyl Green). 1 A. Paired dorsal tentacles on posterior margin of peristomium shifted posteriorly over anterior setigerous segments. 2 1 B. Paired dorsal tentacles on posterior margin of peristomium or anterior achaetous segment, not shifted posteriorly over setiger- ous segments. 4 2 B. Dorsal tentacles shifted dorsally over setiger 1. 3 2 B. Dorsal tentacles shifted dorsally over setigers 4‒7; with distinct MG staining pattern. C. bansei 1 3 A. With distinct achaetous segment preceding setiger 1, bearing first pair of branchiae; all spines in posterior cinctures unidentate; no MG staining pattern. C. careyi n. sp. 3 3 B. Without distinct achaetous segment preceding setiger 1, first pair of branchiae on setiger 1; ventral-most spine in posterior neu- ropodia of cinctures bidentate; with distinct MG staining pattern. C. lunula 1 4 A. Posterior noto- and neuropodial spines with sharply pointed with recurved tip extending posteriorly and fused with shaft form- ing blunt tip. 5 4 B. Posterior noto- and neuropodial spines sharply pointed or blunt, not with recurved tip. 7 5 A First pair of branchiae on setiger 1; no MG pattern. C. commonalis 1 5 B. First and second pair of branchiae both on setiger 1. 6 6 A. Posterior spines from posterior third of body, or about setiger 65 in neuropodia and setiger 70 in neuropodia; dorsal longitudi- nal groove absent; with thin ridge along ventral midline; posterior cinctures well developed, with 26‒29 spines on a side, over- lapping at dorsal midline of each cincture; MG staining prostomium and peristomium, but with clear unstained curved dorsal band between at posterior margin of prostomium. C. allanotai 2 6 B. ...