Siriella lacertilis Talbot, 2009

Daneliya, Mikhail, Price, W. Wayne & Heard, Richard W., 2018, Revision of the Siriella brevicaudata species group (Crustacea: Mysida: Mysidae) from the West Indo-Pacific, European Journal of Taxonomy 426, pp. 1-80 : 33-34

Siriella lacertilis Talbot, 2009

Siriella lacertilis Talbot, 2009: 26 , figs 16–18.

Siriella lacertilis – Anderson 2010: 22 (checklist).

Diagnosis

Carapace with anterodorsal margin almost evenly rounded, not covering subrostral process. Carapace dorsal surface with slight cephalic tubercle and postcervical elevation. Eyes red-brown. Telson about 0.7 times as long as last abdominal somite and barely reaching level of distolateral spiniform setae of uropodal exopod, 1.7 times as long as wide anteriorly and 1.4 times as wide anteriorly as posteriorly; apically truncated, with tapering lateral margins. Telson lateral margins with three anterior and nine posterior spiniform setae; among the latter anterior seven spiniform setae short and two posterior long; terminal posterolateral pair of spiniform setae 1.1–1.2 times as long as subterminal and 0.25 times as long as telson; subterminal pair of spiniform setae 1.8–2.0 times as long as preceding posterolateral. Telson apically with three minute, but clearly visible central spinules, about 0.13–0.16 times as long as posterolateral terminal pair of spiniform setae; without emargination. Labrum with anterior spine short, but well-established, about 0.1–0.15 times as long as rest of labrum. Maxilla 1 with apical robust serrate setae. Maxilla 2 endopod segment 2 with four distolateral setae. Pereopod 1–3 merus 4.1 times as long as wide. Uropodal exopod 3.9 times as long as wide; segment 1 is 1.4–1.5 times as long as segment 2, with three distolateral spiniform setae in both sexes. Uropodal endopod with 14 or 15 medial spiniform setae in both sexes; terminal not reaching apex of ramus.

Material examined

Holotype

AUSTRALIA: ♂, Queensland, Lizard Island, near Research Point , reef at NW edge of lagoon, 14°40′ S, 145°28′ E, above sand near reef, overnight, STL-78- F 4, fixed trap, 13–14 Jan. 1978, M. S. Talbot leg. ( AM P.74061).

Paratype (labeled as allotype)

AUSTRALIA: ♀, Queensland, Lizard Island, lagoon centre, 14°40′ S, 145°28′ E, 0 m, surface plankton tow, STL-78- N 7, 8 Jan. 1978 (23:42), M. S. Talbot leg. ( AM P.74062).

Other material

AUSTRALIA: 1 immature ♂, Queensland, Lizard Island, lagoon, 14°40′ S, 145°28′ E, 24 Sep 1977, P. Slattery leg., previously identified as S. vincenti by M. S. Talbot 1978 ( AM P.34340).

Comparison

Siriella lacertilis is distinguished from all other species of the brevicaudata group by having the shortest telson in relation to the last abdominal somite (> 0.8 times as long as the last abdominal somite in other species) and uropodal exopod with the longest segment 2 (about half as long as segment 1 in other species). Also the pattern of posterior spiniform setae on the telson is specific, with two long graded apical spiniform setae followed by seven distinctly shorter ones. In fact, the terminal spiniform setae of the telson, which constitute 0.25 of its length, are the third longest after those of S. gibbosa and S. brevicaudata . Talbot (2009) also compared S. lacertilis with the species that are currently included in the brevicaudata group but were previously a part of the thompsoni group of Ii (1964); she found it to be most closely related to S. brevicaudata . However, we found that S. lacertilis is most similar to the newly described S. muranoi sp. nov. (see differences in the comparison section for that species). Body length of male 5.0– 6.7 mm, females 5.0– 6.3 mm ( Talbot 2009).

Distribution

So far known only from the type locality, Lizard Island (Great Barrier Reef, Queensland, Australia) ( Talbot 2009) ( Fig. 1 ).

Habitat

Reefs and lagoon bottom ( Talbot 2009).

Remarks

Studying the mysid fauna of the Great Barrier Reef around Lizard Island in the late 1970 s to early 1980 s, Talbot (2009), together with the material described here as S. talbotae sp. nov., found and described S. lacertilis . Probably unfamiliar with the work of Murano & Fukuoka (2008), where the brevicaudata group was established, and which was published at about the same time, Talbot included the species in the thompsonii group, following the previous view of Ii (1964). Here, S. lacertilis is transferred to the brevicaudata group. Talbot (2009) also provided a rather broad diagnostic description of S. lacertilis , and we have attempted here to single out those characters which distinguish it from other species of the group (see the Diagnosis above and Table 1 ).

Figures

Fig. 1. Distribution of species in the Siriella brevicaudata species group. Question mark (?) indicates published record requires verification.