Eogammarus barbatus ( Tzvetkova, 1965 )

Tomikawa, Ko, Morino, Hiroshi, Toft, Jason & Mawatari, Shunsuke F., 2006, A revision of Eogammarus Birstein, 1933 (Crustacea, Amphipoda, Anisogammaridae), with a description of a new species, Journal of Natural History (J. Nat. Hist.) 40 (17 - 18), pp. 1083-1148 : 1095-1100

publication ID	https://doi.org/ 10.1080/00222930600828859
publication LSID	lsid:zoobank.org:pub:41F5583D-BD6D-4FFF-961F-39AA6A6ECCE8
persistent identifier	https://treatment.plazi.org/id/BF741C1D-B21C-572B-FE18-870EFE8FAF7F
treatment provided by	Felipe
scientific name	Eogammarus barbatus ( Tzvetkova, 1965 )
status

Treatment

Eogammarus barbatus ( Tzvetkova, 1965) View in CoL

[Japanese name: Kebuka togeo yokoebi, new]

( Figures 5–8 View Figure 5 View Figure 6 View Figure 7 View Figure 8 )

Anisogammarus (Eogammarus) barbatus Tzvetkova 1965, p 351 View in CoL , Figure 1 View Figure 1 ; 1972, p 214; 1975, p 121–125, Figures 46, 47.

Eogammarus barbatus: Bousfield 1979, p 314 View in CoL .

Material examined

Japan. „, 20.2 mm, ♀, 17.1 mm, Makinouchi (43 ° 219350N, 145 ° 379430E), Nemuro City, Hokkaido, 25 April 2003, collected by K. Tomikawa. 3 „, 17.5–24.9 mm, Shiraoi River (42 ° 339380N, 141 ° 199450E), Shiraoi Town , Shiraoi County, Hokkaido, 22 February 1990, collected by K. Kuribayashi. Russia. „, 19.0 mm, Achomten Bay , Kamchatka, 19 August 1933, collected by N. Spasskii. „, 16.5 mm, CMNC 1980-0134 , Antonova, 2 km from mouth of stream, Sakhalin Island, 4 October 1966 , collected by V. A. Kudrjaschov. ♀, 12.5 mm, CMNC 2004-1025 , De-Kastri Bay , 19 August 1948, collected by O. B. Mokijewsky.

Description of male (20.2 mm from Makinouchi)

Antenna 1 ( Figure 5A View Figure 5 ): peduncular articles 1:2: 3 in ratio of 1.0:0.9:0.5; article 1 with robust seta posterodistally, posterior margin with two pairs and four clusters of setae and a single seta; posterior margin of article 2 with two pairs and four clusters of setae; posterior margin of article 3 with two pairs and cluster of setae; accessory flagellum seven-articulate; primary flagellum 29-articulate, each article with one short aesthetasc ( Figure 5B View Figure 5 ). Antenna 2 ( Figure 5C View Figure 5 ): 0.8× length of antenna 1; peduncular article 1 with apical setae; articles 4 and 5 about equal in length; posterior margin of article 4 with five clusters of setae; posterior margin of article 5 with six clusters of setae; flagellum 15-articulate, with cup-calceoli ( Figure 5D View Figure 5 ).

Pleon: smooth.

Mandible ( Figure 5G, H View Figure 5 ): palp article 2 with 19 marginal and 30 submarginal setae; palp article 3 as long as article 2 length, with three clusters of A-setae, pair of B-setae, and a single B-seta. Maxilla 1 ( Figure 5I View Figure 5 ): inner plate with 22 plumose setae; palp article 1 with three setae on outer margin, article 2 with six setae on outer margin and seven stout and five slender setae apically. Maxilla 2 ( Figure 5J View Figure 5 ): inner plate with 19 facial setae. Maxilliped ( Figure 5K–M View Figure 5 ): inner plate with three apical and two medial bent, stout setae; outer plate beyond middle of palp article 2; outer distal corner of palp article 2 with cluster of setae.

Gnathopod 1 ( Figure 5N View Figure 5 ): palmar margin of propodus ( Figure 5P View Figure 5 ) lined with 11 inner and six outer robust striated peg setae. Gnathopod 2 ( Figure 5Q View Figure 5 ): palmar margin of propodus ( Figure 5S View Figure 5 ) lined with 10 inner and eight outer robust striated peg setae, inner stiff pectinate seta.

Pereopods 3–4 ( Figure 6A, B View Figure 6 ): basis with setose anterior and posterior margins; merus, carpus, and propodus length ratio 1.0:0.9:0.9 for pereopod 3, 1.0:0.9:1.0 for pereopod 4. Pereopod 5 ( Figure 6C View Figure 6 ): inner posterodistal part of basis with robust seta. Pereopod 6 ( Figure 6D View Figure 6 ): longest posteromarginal seta of basis 0.8× width of ischium. Pereopod 7 ( Figure 6E View Figure 6 ): posterodistal margin with robust seta.

Pleopods ( Figure 6F–H View Figure 6 ): retinacula paired ( Figure 6G View Figure 6 ). Epimera 1–3 ( Figure 6L–N View Figure 6 ): with setose anteroventral margins.

Uropod 1 ( Figure 7A View Figure 7 ): inner ramus length 0.8×, outer ramus length 0.7× peduncle length; peduncle with robust marginal setae and slender basofacial seta; inner ramus with two robust inner marginal setae; outer ramus with one inner and one outer robust marginal setae. Uropod 2 ( Figure 7B View Figure 7 ): inner ramus length 0.9× and outer 0.7× peduncle length; peduncle with robust marginal setae; inner ramus with two robust inner marginal setae; outer ramus with a robust outer marginal seta. Uropod 3 ( Figure 7C View Figure 7 ): inner ramus length 0.2× outer ramus length, with plumose setae; outer margin of outer ramus with five clusters of robust setae and slender simple setae; terminal article length 0.1× proximal article length. Telson ( Figure 7D View Figure 7 ): length 1.1× width, with robust apical and distolateral setae, slender apical and distolateral setae, and apical and distolateral penicillate setae; robust apical setae longer than slender setae; cleft 62%.

Description of female (17.1 mm from Makinouchi)

Antenna 1 ( Figure 8A View Figure 8 ): accessory flagellum six-articulate; primary flagellum 37-articulate, each article with one short aesthetasc. Antenna 2 ( Figure 8B View Figure 8 ): peduncular article 4 about as long as article 5; article 4 with five clusters of posteromarginal setae; article 5 posterior margin with one pair and four clusters of setae; flagellum 11-articulate, with cup-calceoli.

Gnathopod 1 ( Figure 8C View Figure 8 ): inner face of coxa strongly setose; palmar margin of propodus ( Figure 8E View Figure 8 ) with 15 robust simple setae on inner distal part. Gnathopod 2 ( Figure 8F View Figure 8 ): palmar margin of propodus ( Figure 8H View Figure 8 ) with two simple and five robust pectinate setae on inner distal part.

Pereopod 6 ( Figure 8K View Figure 8 ): longest posteromarginal seta of basis 0.5× width of ischium. Pereopod 7 ( Figure 8L View Figure 8 ): longest posteromarginal seta of basis 1.0× width of ischium.

Uropod 3 ( Figure 8M View Figure 8 ): outer margin of outer ramus with six clusters of robust setae, inner margin with five clusters of robust setae.

Variation

The number of clusters of setae on peduncular articles of both antennae 1 and 2 varies from four to six. The number of clusters of robust setae on the outer margin of the outer ramus of uropod 3 varies from four to six. The telson is as long as wide in some specimens.

Remarks

Eogammarus barbatus is closely similar to E. itotomikoae . Diagnostic characters between the two species are mentioned in the remarks for E. itotomikoae (see above).

Distribution

Hokkaido, Kamchatka, Sakhalin, Shakotan Island (Kuril Islands), Udskaya Gulf (Sea of Okhotsk coast of Russia) .

Habitat

River mouth.