Cephalomastax brevis, IWATA, 1957
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publication ID |
https://doi.org/ 10.1093/zoolinnean/zlac015 |
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publication LSID |
lsid:zoobank.org:pub:78C56409-FCCF-4116-8D8C-FF66B247C56C |
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DOI |
https://doi.org/10.5281/zenodo.7036921 |
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persistent identifier |
https://treatment.plazi.org/id/038A8132-EE7B-ED54-FC6C-CCD4FD8FFEA4 |
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treatment provided by |
Plazi |
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scientific name |
Cephalomastax brevis |
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CEPHALOMASTAX BREVIS IWATA, 1957 View in CoL View at ENA
( FIGS 2C View Figure 2 , 5A–E View Figure 5 )
Cephalomastax brevis Iwata, 1957: 5–7 View in CoL , pl. I, fig. 9, pl. II, fig. 7, pl. III, figs 1–7; Kajihara, 2017: 423, fig. 16.2h.
Material examined: Two non-type specimens. ICHUM 6267 View Materials , serial transverse sections, 8 µm thick, Mallory, 13 slides, along with extracted total DNA; 19 February 2014, dredged between 35°5′56″N, 139°34′10″E, 249 m depth, and 35°5′46″N, 139°34′04″E, 309 m depth, at station 2 of the 2 nd JAMBIO Coastal Organism Joint Survey ( Nakano et al., 2015), collected by H. Kajihara. ICHUM 6304 View Materials , extracted total DNA and body fragment preserved in 99% EtOH, collection data as for ICHUM GoogleMaps 6267.
Sequences: From ICHUM 6267 View Materials : LC178640 View Materials , 28S (2096 bp). From ICHUM 6304 View Materials : LC178651 View Materials , H3 (331 bp); LC178689 View Materials , 16S (510 bp); LC190961 View Materials , COI (658 bp) .
Description: Two fragments of anterior body, each about 2.5 cm long and 2 mm wide. Background body colour pale peach, dorsally maroon; dorsal pigmentation not covering head ( Figs 2C View Figure 2 , 5A, B View Figure 5 ). Head not demarcated from body in normal state, but clear demarcation obvious when animal contracted ( Fig. 5A, B View Figure 5 ). Transverse cephalic furrow encircling head; secondary furrows present. Proboscis pore slightly behind tip of head ( Fig. 5B View Figure 5 ). Mouth behind cephalic furrow ( Fig. 5B View Figure 5 ). Anterior proboscis wall composed of glandular epithelium, outer longitudinal muscle layer, neural plexus, inner longitudinal muscle layer, and circular muscle endothelium ( Fig. 5C, D View Figure 5 ); longitudinal muscle fibres abutting neural plexus running diagonally, often penetrating nervous tissue ( Fig. 5D View Figure 5 ). Posterior proboscis wall composed of glandular epithelium, longitudinal muscle layer and endothelium ( Fig. 5C View Figure 5 ). Rhynchocoel wall composed of meshwork of interwoven longitudinal and circular (and maybe also diagonal) muscle fibres; circular component denser in inner portion ( Fig. 5E View Figure 5 ).
Distribution: Known only from the type locality, Sagami Bay, Japan ( Iwata, 1957; present study).
Remarks: Because Cephalomastax brevis was originally described from a preserved specimen, the external features in the living state were unknown. However, Iwata’s (1 9 5 7: 6) description of the appearance of the preserved type specimen (before sectioning) matches perfectly our observations in that the ‘body is pale chestnut in colour on the dorsal side except only the portion of the neck which is whitish; the ventral surface is white’. Other features such as the absence of eyes and the unique arrangement of the proboscis muscle layers in relation to the nerve plexus (outer longitudinal, nerve plexus, inner longitudinal, and inner circular muscle layers) add more credence to the species identification of our specimens.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
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Cephalomastax brevis
| Kajihara, Hiroshi, Abukawa, Shushi & Chernyshev, Alexei V. 2022 |
Cephalomastax brevis
| Kajihara H 2017: 423 |
| Iwata F 1957: 7 |