Colobomatus absens, Madinabeitia & Tang & Nagasawa, 2013
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publication ID |
https://doi.org/ 10.1080/00222933.2012.737483 |
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publication LSID |
lsid:zoobank.org:pub:BEB140D5-8936-4B47-B8B9-738BFABF37E1 |
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DOI |
https://doi.org/10.5281/zenodo.4631783 |
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persistent identifier |
https://treatment.plazi.org/id/813A87D1-FF96-3A02-564E-FF134963FA6A |
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treatment provided by |
Carolina |
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scientific name |
Colobomatus absens |
| status |
sp. nov. |
Colobomatus absens sp. nov.
( Figure 6 View Figure 6 A–E)
Material examined
Holotype female (NSMT-Cr 21863) and 2 paratype females (NSMT-Cr 21864), from head canals of two Pterocaesio digramma (Bleeker) ( Perciformes : Caesionidae ), captured in the western North Pacific Ocean off Ishigaki-jima Island and subsequently purchased at Yaeyama Fisheries Cooperative (24 ◦ 19 ′ N, 124 ◦ 0 ′ E) in Ishigaki, Ishigaki-jima Island, 12 May 2010.
Description
Adult female. Body ( Figure 6A View Figure 6 ) 1.89 (1.87–1.91) mm long (excluding cephalic processes and caudal rami) (n = 3). Pre-oral area of cephalosome ( Figure 6A View Figure 6 ) bearing one anterior, spinulose pair of anteriorly directed and pointed processes. Cephalosome round and constricted at posterior margin. First pedigerous somite cylindrical, forming short neck; first pair of legs on ventral surface near anterior constriction. Second to fourth pedigerous somites fused, elongated, widest at posterior end and bearing one pair of anterolateral processes; latter with spinulose ornamentation and tapering into pointed tips ( Figure 6E View Figure 6 ). Fifth pedigerous somite short, narrower than preceding tagma. Genital somite ( Figure 6A View Figure 6 ) bearing one ventrolateral pair of slender, spinulose and posterolaterally directed processes; latter as long as anterior pair of thoracic processes. Abdomen ( Figure 6A View Figure 6 ) indistinctly three-segmented, with single dorsomedian process at posterior end projecting between caudal rami; process spinulose, pointed at tip and as long as caudal rami. Caudal ramus ( Figure 6A View Figure 6 ) posterolaterally directed, spinulose, tapering into pointed tips.
Antennule ( Figure 6B View Figure 6 ) arising near base of cephalic processes, apparently foursegmented with armature of 1, 8, 4 and 5 + 2 aesthetascs. Antenna ( Figure 6C View Figure 6 ) modified, forming large, longitudinally divided anterior margin of buccal capsule; latter ( Figure 6A,C View Figure 6 ) tube-like, projecting ventrally. Labrum and mandibles not seen. Maxillule ( Figure 6C View Figure 6 ) anteriorly located in buccal capsule and bearing one apical spine. Maxilla ( Figure 6C View Figure 6 ) large, apparently one-segmented and armed with claw apically. Maxilliped ( Figure 6C View Figure 6 ) blunt and unarmed. Labium ( Figure 6C View Figure 6 ) undivided, anteriorly rounded. Posterior rim of buccal capsule undivided.
Leg 1 ( Figure 6D View Figure 6 ) uniramous; protopod completely fused to somite, represented by long, lateral surface seta; exopod indistinctly two-segmented, with unarmed basal segment and four elements on distal segment. Legs 2 and 3 not observed.
Etymology
The species epithet, absens , is taken from the Latin for “missing”. It refers to the absence of a posterior pair of thoracic processes in the female.
Remarks
The presence of a posteriorly directed, median process at the posterior end of the abdomen of C. absens sp. nov. is a character shared with C. haeckeli , C. goodingi , C. exilis , C. collettei , C. creeveyae and C. ornatus . However, C. absens sp. nov. can be easily distinguished from these five species and all other congeners by having only one pair rather than two pairs of thoracic processes.
This study represents the first report of a species of Colobomatus parasitic in the family Caesionidae .
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.