Siriella lingvura Ii, 1964

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 : 35-36

Siriella lingvura Ii, 1964

Siriella lingvura Ii, 1964: 78 , figs 17–18.

Siriella lingvura – Mauchline & Murano 1977: 76 (checklist). — Valbonesi & Murano 1980: 212, fig. 1. — Murano 1990: 191, fig. 2. — Müller 1993: 40 (catalogue). — Fukuoka & Murano 1997: 521, fig. 2c–e. — Murano & Fukuoka 2008: 35. — Anderson 2010: 22 (checklist). — Yamada et al. 2011: 336.

Diagnosis

Carapace with anterodorsal margin almost evenly rounded, not covering subrostral process. Carapace with smooth dorsal surface. Eyes dark purple. Telson 0.9 times as long as last abdominal somite and barely reaching level of distolateral spiniform setae of uropodal exopod, 1.6–1.8 times as long as wide anteriorly and 1.45–1.5 times as wide anteriorly as posteriorly; lateral margins slightly tapering, with four to six anterior and 9 to 11 posterior spiniform setae, gradually increasing in length towards apex; terminal posterolateral pair of spiniform seta 0.13–0.14 times as long as telson and 1.2–1.6 times as long as subterminal; subterminal pair of spiniform setae 1.1–1.4 times as long as preceding posterolateral. Telson apical margin with three minute, but clearly visible central spinules, about 0.19–0.23 times as long as terminal pair of spiniform setae. Telson apically without emargination. Antennal scale 2.8–3.4 times as long as wide. Labrum with anterior spine rather short, but developed, about 0.15 times as long as rest of labrum. Maxilla 1 with apical robust smooth setae. Maxilla 2 endopod segment 2 with three or four distolateral setae. Pereopod 1–3 merus 3.5 times as long as wide; carpopropodus 0.8 times as long as merus. Uropodal exopod 3.6–3.7 times as long as wide; segment 1 is 1.8–2.2 times as long as segment 2, with four–five distolateral spiniform setae in both sexes. Uropodal endopod with 15 or 16 medial spiniform setae in both sexes; distal terminal spiniform seta not reaching apex of ramus.

Type material

Syntypes (no clear statement in the original description)

JAPAN: 2 ovigerous ♀♀, 7 mm long (one female), Nagatsuro, Kamo District, Shizuoka Prefecture, night, plankton net with light, 17 Aug. 1943, donated by Y. Okada (Ii’s collection, 432a). The specimens are probably lost (Fukuoka and Murano, pers. comm.).

Type locality

Central Japan, Izu Peninsula, Sagami Bay off Nagatsuro.

Comparison

Siriella lingvura is characterised by the largest number of anterolateral spiniform setae of the telson (five or six) in the group, which is three or four in other species. It is evidently most closely related to S. tabaniocula sp. nov. (see differences in the comparison section for that species). Siriella lingvura is also closely related to S. hanseni and S. muranoi sp. nov. From S. hanseni it is distinguished by the pattern of posterior setation of the telson: 9 to 11 gradually increasing in length apically, with the terminal pair clearly distinguished from the subterminal, while represented by four to nine short and three to six nearly equally long apical spiniform setae in S. hanseni . It is also distinguished by the clearly established, though small, spine of the labrum and the larger number of inner spiniform setae on the uropodal endopod (15 or 16 against 10 to 13 in S. hanseni ). Differences from S. muranoi sp. nov. can be seen in the corresponding comparison section. Body length of male 4–6.5 mm, female 4–7 mm ( Ii 1964; Valbonesi & Murano 1980; Murano 1990; Murano & Fukuoka 2008), with specimens from the Ryukyu Archipelago (southern part of the species range) generally smaller than those from mainland Japan ( Murano & Fukuoka 2008).

Geographic variation

In mainland Japan the terminal posterolateral pair of spiniform setae is 1.5–1.6 times as long as the subterminal (as depicted by Ii 1964); however, the ratio is 1.2–1.3 in the Ryukyu Archipelago (as in Murano 1990).

Distribution

Siriella lingvura is the northernmost species in the group, found so far exclusively in Japanese waters: mainland and nearby islands – Sagami Bay (type locality), Tanabe Bay ( Valbonesi & Murano 1980), Kozu Island, Nomo of Nagasaki, Tanegashima Island ( Murano & Fukuoka 2008), Tokyo Bay ( Yamada et al. 2011); Ryukyu Archipelago – Akajima Island ( Murano 1990; Murano & Fukuoka 2008), Iriomote Island ( Fukuoka & Murano 1997; Murano & Fukuoka 2008), Ishigaki Island ( Murano & Fukuoka 2008) ( Fig. 1 ).

Figures

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