Lowryella wadai, Morino & Miyamoto, 2016

Morino, Hiroshi & Miyamoto, Hisashi, 2016, A New Talitrid Genus and Species, Lowryella wadai, from Estuarine Reed Marshes of Western Japan (Crustacea: Amphipoda: Talitridae), Species Diversity 21, pp. 143-149 : 145-149

publication ID	https://doi.org/ 10.12782/sd.21.2.143
publication LSID	lsid:zoobank.org:pub:6FBE8B84-5689-4E76-A9E1-2E901AA8BCA1
persistent identifier	https://treatment.plazi.org/id/1D41AC08-5148-4BAB-A8E9-61C58D433E0D
taxon LSID	lsid:zoobank.org:act:1D41AC08-5148-4BAB-A8E9-61C58D433E0D
treatment provided by	Felipe
scientific name	Lowryella wadai
status	sp. nov.

Treatment

Lowryella wadai View in CoL sp. nov.

[New Japanese name: Yoshihara-hamatobimushi] ( Figs 2–5 View Fig View Fig View Fig View Fig )

Type material. Holotype (NSMT-Cr 24358), male 9.9 mm, Misho Bay (estuary of Sozu river, Phragmites marsh), Ainan-cho , Ehime Pref., 20 April 2004, K. Wada coll. Allotype (NSMT-Cr 24359), female 8.2 mm, same data as holotype. Paratypes: ovig. female (NSMT-Cr 24361), 8.0 mm, same data as holotype; male (NSMT-Cr 24360), 6.5 mm, same data as holotype; female (NSMT-Cr 24362), 7.8 mm, same data as holotype; 2 juveniles (NSMT-Cr 24363), same data as holotype; ovig . female (NSMT-Cr 24364), estuary of Kitagawa river ( Phragmites marsh), Nobeoka city, Miyazaki Pref ., 5 June 2004, K . Wada coll .

Description of male (Holotype, 9.9 mm). Eyes ( Figs 2 View Fig , 3A View Fig ) large, longest diameter ca. half of head length, spherical in dorsolateral view, contiguous dorsally. Antenna 1 ( Fig. 3B View Fig ) with peduncular articles 1–3 subequal in length; flagellum with 4 articles. Antenna 2 ( Figs 2 View Fig , 3C View Fig ) with peduncular article 5 subequal in length to articles 3 and 4 combined; flagellum with 10 articles.

Upper lip ( Fig. 3D View Fig ), lower lip ( Fig. 3E View Fig ), and maxillae 1and 2 ( Fig. 3F, G View Fig ) as described in generic diagnosis or illustrated in respective figures. Gnathopod 1 ( Fig. 3L, M View Fig ) with broad carpus and propodus; carpus ca. 1.3 times as long as propodus; propodus ca. 0.7 times as broad as long, with palmar margin transverse, far exceeding tip of dactylus; lateral surface of propodus with submarginal row of 5 setae. Gnathopod 2 ( Fig. 3P View Fig ) with posterior cusp of coxa indistinct, palmar margin of propodus subequal to posterior margin in length, distal corner of palm weakly angulate, posterior margin parallel to anterior margin; dactylus robust. Locking robust-setae on propodi of pereopods 3–7 well-developed ( Fig. 4B View Fig [arrow], D, F, H; not illustrated in Fig. 4J View Fig ). Pereopods 3 ( Fig. 4A View Fig ) and 4 ( Fig. 4C View Fig ) each with coxa bearing weak posterior cusp. Pereopod 4 slightly shorter than pereopod 3. Pereopods 5 ( Fig. 4E View Fig ) and 6 ( Fig. 4G View Fig ) each with basis strongly lobate posteroventrally. Meri and carpi of pereopods 5–7 broad, ca. twice as wide as width of respective propodi. Pereopod 7 ( Fig. 4I View Fig ) with basis not lobate posteroventrally; propodus with ca. 10 serrate setae mediodistally ( Fig. 4J, K View Fig ).

Pleonite side plates ( Fig. 5A–C View Fig ) weakly acuminate posteroventrally, each posterior margin with single tiny seta. Peduncles of pleopods 1–3 ( Fig. 5D, F, G View Fig ) each with 2 retinacula ( Fig. 5E View Fig ), margins bare or with a few setae; rami with 8–10 articles, as long as or slightly longer than respective peduncles.

Uropod 1 ( Fig. 5H View Fig ) with peduncle bearing 4 outer and 2 inner marginal robust setae; inner ramus with 3 dorsomarginal robust setae. Uropod 2 ( Fig. 5I View Fig ) with peduncle bearing 2 outer and 2 inner marginal robust setae; outer ramus with 1 marginal robust seta; inner ramus with 1 lateral and 2 dorsomarginal robust setae. Uropod 3 ( Fig. 5J View Fig ) with broad peduncle equipped with 4 robust setae on dorsal margin; ramus slightly shorter than peduncle, with 1 marginal and 5 apical robust setae. Telson ( Fig. 5K View Fig ) tapering distally, with suture in middle; each lobe with 2 subapical and 3 apical robust setae.

Description of female (Allotype, 8.2 mm). Mandibles ( Fig. 3H, I View Fig ) as in generic diagnosis. Article 4 of maxillipedal palp reduced ( Fig. 3J, K View Fig ), masked by marginal setae on dorsal side and discernible from ventral side. Gnathopod 1 ( Fig. 3N, O View Fig ) with basis and ischium each bearing small bulge with scabrous surface; merus and carpus lacking pellucid lobe; posterior margin of propodus slightly broadened distally, with scabrous surface; lateral surface of propodus with submarginal row of 5 setae; palmar margin transverse, slightly exceeding tip of dactylus. Gnathopod 2 ( Fig. 3Q View Fig ) with coxa bearing blunt posterior cusp, merus with distinct pellucid lobe. Pereopods more robust than those of male (see Fig. 4M and 4L View Fig for pereopods 3 and 7, respectively). Pereopod 7 with posteroventral lobe on basis; propodus lacking setal tuft at distal end. Oostegites of gnathopod 2 and pereopods 3 and 4 subovate with ca. 30 simple-tipped setae ( Fig. 3R View Fig for oostegite of gnathopod 2). Oostegite of pereopod 5 small, with 7 setae ( Fig. 4N View Fig ).

Egg number 17 (paratype, NSMT-Cr 24361, 8.0 mm).

Etymology. This species is named for Dr Keiji Wada, who has made great efforts in extensive surveys to elucidate the estuarine fauna in Japan, and who forwarded the present material to us for study.

Distribution. So far only known from estuarine Phragmites reed marshes at two localities (Shikoku and Kyushu) that face the Bungo Channel in western Japan ( Fig. 1 View Fig ).

Remarks. In a smaller paratype female (NSMT-Cr 24361, 8.0 mm), the bulge on the posterodistal margin of the ischium is hardly developed but that on the basis is distinct. The allotype and paratypes display fewer articles in the antennal flagella than the holotype does: the number of articles of antennae 1 and 2 are three and eight (vs. four and 10 in the holotype), respectively. This is apparently correlated with body size (8.0– 8.2 mm in the allo- and paratypes vs. 9.9 mm in the holotype).

An extensive survey of tidal flats at 157 localities all over Japan, ranging from Hokkaido to Kyushu and including the Ryukyu and the Ogasawara Archipelagos, so far has revealed the presence of Platorchestia spp. , Paciforchestia spp. (now Pyatakovestia Morino and Miyamoto, 2015 ; see Morino and Miyamoto 2015b), and Traskorchestia ochotensis (Brandt, 1851) in such habitats ( Biodiversity Center of Japan 2007). Among that survey’s samples, we discovered the present additional talitrid, Lowryella wadai gen. et sp. nov., at two adjacent localities in western Japan ( Fig. 1 View Fig ). This may indicate a highly endemic distribution of this species, but the amphipod fauna of estuarine habitats in Japan, including reed marshes, has not so far received much attention. Further studies may expand the distributional range of this species or reveal related genera or species. Intensive sampling in selected estuarine reed marshes around western Japan may be one way of casting light on this subject.