Caligus sp. 2
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publication ID |
https://doi.org/10.11646/zootaxa.5686.2.1 |
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publication LSID |
lsid:zoobank.org:pub:FAE3CA10-9DC4-45E0-819E-6F3A02CE7F20 |
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persistent identifier |
https://treatment.plazi.org/id/5E1F87E2-6C6F-9A0F-FF6D-F997FE13FF38 |
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treatment provided by |
Plazi |
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scientific name |
Caligus sp. 2 |
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( Figs 31A View FIGURE 31 – 32E View FIGURE 32 )
Host: Coryphaena hippurus Linnaeus ( Coryphaenidae : Carangiformes)
Locality: Off west coast South Africa (Atlantic Ocean)
Material examined: 1♀
Material collected: 1♀ from C. hippurus
Adult female ( Fig. 31A View FIGURE 31 ) cephalothorax more than half of total length; genital complex slightly longer than wide, posterolateral corners lobate; abdomen small, 1-segmented, about ⅓ length of genital complex; antenna (a2) with tapering proximal process (arrowed), claw strongly curved ( Figs 31B, C View FIGURE 31 ); post-antennal process (pap) tine weakly curved, blunt-ending ( Figs 31B, C View FIGURE 31 ); maxillule with dentiform posterior process (mpp) slightly curved, blunt tip surrounded by marginal flange ( Figs 31B, C, D View FIGURE 31 ); sternal furca (sf) with divergent, blunt-ended tines slightly curved inwards distally, surrounded by marginal flange ( Fig. 31E View FIGURE 31 ); leg 1 last exopodal segment with 3 posterior pinnate setae (ps), terminal seta 4 (4) longer than terminal spines 1–3 ( Figs 31F View FIGURE 31 , 32A View FIGURE 32 ), spine 2 (t2) and 3 (t3) with accessory processes ( Fig. 32A View FIGURE 32 ); leg 2 exopodal segment 1 and 2 distolateral spines (arrowed) lying obliquely over surface of ramus ( Fig. 32B View FIGURE 32 ), endopodal segments with setules (arrowed) along outer margins ( Fig. 32C View FIGURE 32 ); leg 3 exopodal segment 1 distolateral spine (ds) curved, slightly shorter than segment 2 ( Fig. 32D View FIGURE 32 ); leg 4 3-segmented with I, IV spines, medial terminal spine (IV) about twice as long as distolateral spine (II) ( Fig. 32E View FIGURE 32 ).
Remarks: This specimen is slightly smaller (3.6 mm) than C. mulli reported before (4.2 mm) with the genital complex of this specimen about 1.1 mm long and slightly longer than wide while that of C. mulli is about 1.7 mm long and about 1.5 times longer than wide. The post-antennal process tine is not conspicuously surrounded by a marginal flange (see Fig. 31C View FIGURE 31 ) while in C. mulli it is (see Fig. 29B View FIGURE 29 ). Leg 2 exopod distolateral spines on the first and second segments are lying slightly obliquely over the surface of the rami with the spine on the first segment almost reaching the middle of the last segment and the spine on the second segment also reaching about the middle of the last segment (see Fig. 32B View FIGURE 32 ) while in C. mulli the spines are lying obliquely over the surface of the rami with the spine on the first segment barely reaching into the next segment (see Fig. 29F View FIGURE 29 ). Leg 3 first exopodal segment distolateral spine in the current specimen is curved, almost reaching the articulation between segments 2 and 3 (see Fig. 32D View FIGURE 32 ) while in C. mulli it is less curved and slightly shorter (see Fig. 30B View FIGURE 30 ). Spines on leg 4 are very similar with the lateral spines in the current specimen maybe slightly longer (see Fig. 32E View FIGURE 32 ) than those in C. mulli (see Fig. 30C View FIGURE 30 ).
Caligus sp. 2 does not fall within one of the eight established Caligus groups. Comparing it with the remaining species, it does not seem like any of the described species has the combined suit of features. Firstly, the posterolateral lobes of the genital complex together with the small abdomen are features not often encountered. Secondly, the combined features of legs 1–4 are also rarely encountered amongst the compared species. The shape of the genital complex almost resembles that of C. deformis Brian (Özak pers. comm.) as do the structure of leg 4, but the body proportions are different and the original description somewhat vague ( Brian 1924). Therefore, this may be a new species, but with only one available specimen it will remain as Caligus sp.
Description of new species
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.