Babr baikali ( Stebbing, 1899 )

Daneliya, Mikhail E., Kamaltynov, Ravil M., Kontula, Tytti & Väinölä, Risto, 2009, Systematics of the Baikalian Babr (Crustacea: Amphipoda: Pallaseidae), Zootaxa 2276, pp. 49-68 : 58-63

Babr baikali ( Stebbing, 1899)

( Figures 3 – 7 )

Gammarus Lovenii Dybowsky, 1874: 137 , Tab. XIII, Fig. 7 , [non G. lovenii Bruzelius, 1859 ]; Pallasea baikali (partim) Stebbing, 1899: 422; Stebbing, 1906: 378; Sowinsky, 1915: 272; Pleuracanthus lovenii Garjajev, 1901: 42 ;

Pallasea (Pallasea) baikali Bazikalova, 1945: 144 ; Barnard & Barnard, 1983: 480; Pallasea kessleri var. inermis Sowinsky, 1915: 265 ;

P. baikali inermis Dorogostaisky, 1922: 123 , Tab. 2, Fig. 4 ;

Pallasea (Pallasea) baikali inermis Bazikalova, 1945: 145 ; Barnard & Barnard, 1983: 480; P. baikali Väinölä & Kamaltynov, 1999: 951 [“ P. baikali M+N”]; P. (Pallasea) baikali baikali Takhteev, 2000: 60 ;

Babr baikali Kamaltynov, 2002: 756 ;

Babr inermis Kamaltynov, 2002: 756 .

Type material. Lectotype, male, 22 mm, “Loveni”, Baikal, 1873 ( ZIN 1/88436). Paralectotypes: 1 juvenile, Baikal ( ZIN 1/88436); 1 male, 27.5 mm, “ Gammarus loewenii” ( ZMH 21667).

Additional material examined. (The following notations are used: sites are mainly listed counterclockwise following shoreline; locality name is followed by a basin code (S=southern, C=central, N=northern main basin of Lake Baikal, see Fig. 1 ); station codes (st.) refer to the cruises of respective years on r/v Obruchev (91-x =1991) and r/v Titov (99-x, 00-x, 06-x and 07-x); collector acronyms are MED=Mikhail Daneliya, RMK=Ravil Kamaltynov, RV=Risto Väinölä; the numbers of specimens examined by different methods are indicated as mor: for morphology, all: for allozymes and mtD: for the mitochondrial COI gene sequence. Museum collection numbers given after the mor: specification are MZH =Zoological Museum, University of Helsinki; LIN=Limnological Institute, Irkutsk, ZIN =Zoological Institute, St. Petersburg).

Kultuk Bay (S), 51°43´N, 103°43´E, sandy beach 0.5 m, 14.09.1998, coll. RV & RMK (mor: 2 MZH 53152; all: 9; mtD: 3);

Kultuk Bay (S), 51°43´N, 103°43´E, 2−3 m sand, 14.09.1998, coll. RV (mor: 2; all: 2)

Kultuk Bay (S), 53º 43'13'' N, 103º42'54'' E (st. 07-64), 0.5–1 m sand, 14.08.2007 coll. RV & MED (mor: 77 MZH 53153; mtD: 2);

same location and date, 2–3 m, sand, stones, vegetation (mor: 19 MZH 53154);

Kultuk Bay (S), 51°43´02´´ N, 103°43´10´´ E (st. 07-62), 10 m, sand, 14.08.2007, coll. MED & RV (mor: 4 MZH 53155, 53175; mtD 1);

Cape Ulan-Koblit (unknown locality), 18 m, mud, algae, 31.07.1916, coll. Baikal Expedition (mor: 1 ZIN);

Budyskaya Guba (Olkhon Island; C), 53°07´37´´ N, 107°29´12´´ E (st. 07-14), 2–3 m, sand, 0 6.08.2007, coll. RV & MED (mor: 33 MZH 53157; mtD: 5);

Olkhon Strait, Khul Bay (C/N), 53°04´N, 106°56´E (st. 91-4), 7−15 m, Charales, 16.08.1991, coll. RMK & RV (mor: 1; all: 2; mtD: 3)

Olkhon Strait, Khul Bay (C/N), 53°04´N, 106°56´E (st. 00-14), 2−9 m, 23.09.2000, coll. RMK & RV (mor: 1; mtD: 1)

Olkhon Strait, Khul Bay (C/N), 53º03'04'' N, 106º55'56'' E (st. 07-15a), 2–3 m, sand, vegetation, 0 6.08.2007, RV & MED (mor: 32 MZH 53158; mtD: 1);

Maloe More strait, Bayan-Shungen Bay (N), 53°15´21´´ N, 107°29´30´´ E (st. 07-16a), 1–2 m, sand, 0 6.08.2007, coll. RV & MED (mor: 49 MZH 53159, 53174; mtD: 5);

Maloe More, Toubdi (N, exact locality unknown), 13.07.1897, coll. Botkin (mor: 1 LIN 854);

Boguchanski Bay (N), 55°25´21´´ N, 109°11´18´´ E (st. 06-14), 0.5–1.5 m, sand, 15.08.2006, RV & MED (mor: 9 MZH 53161; mtD: 2);

off Yarki Island (N), 55°45´N, 109°40´E (st. 91-8), 20.08.1991, coll. RMK & RV (mor: 1; all: 43; mtD: 3);

Frolikha Bay (N), 55°31´N, 109°51´E (st. 99-54), 13−30 m, 26.7.1999, coll. RV & RMK (mor: 1; mtD: 3);

Ayaya Bay (N), 55°27´22´´ N, 109°53´58´´ E (st. 06-22a), 0.5–1.5 m, sand, 15.08.2006, coll. RV & MED (mor: 16 MZH 53160; mtD: 1);

Davsha Bay (N), 54°20´N, 109°29´E (st. 07-34b), 2 m, sand, 0 9.08.2007, coll. RV & MED (mor: 36 MZH 53162, 53173; mtD: 5);

Senogda Bay (N, 55°34´N, 109°13´E), st. 633, 2 m, sand, 0 9.07.1955, coll. Bazikalova (mor: 1 LIN 868);

Irinda Bay (N), 54°50´N, 109°40´E (st. 91-10), 21.08.1991, coll. RMK & RV (mor: 1; all: 9; mtD: 3);

1 km S from mouth of Malaya Cheremshana River (N), 54°00´N, 109°24´E (st. 99-39), 25.7.1999, 15– 25 m, coll. RMK & RV (mor: 1; mtD: 1);

Chivyrkui Gulf, Zmeinaya Bay & Pesochnaya Bay (N), 53°45´N, 109°01´E (st. 00-28/29), 1m / 4m sand, 25.9.2000, coll. RV (mor: 2; mtD: 2);

Chivyrkui Gulf, Kurbulik (N), 53°42´N, 109°02´E (st. 91-11), sand, 22.08.1991, coll. RV (all: 7).

Barguzin Bay, off Cape Kholodyanka (C), 53°23´N, 108°59' E (st. 99-27), 4−7 m, sand, 23.07.1999, coll. RV & RMK (mor: 3 MZH 53156; mtD: 3);

Bezymyannaya Bay (C), 53°02´N, 108°18´E (st. 99-21), 23.7.1999, 2.5−4 m sand, coll. RMK & RV (mor: 2 MZH 53170; mtD: 3);

Talanki Bay (C, 52°42´N, 107°41´E), st. 1194, 10 m, 21.07.1957, coll. Bazikalova (mor: 1 LIN 867);

Off Selenga delta mouth (S/C), 2 m, mud, 0 8.05.1915 (mor: 12 ZIN 2/88439 " Pall. baikali inermis Sow., det. Dorogostaisky");

Off Severnoe Ustie mouth (S/C, 52°23´N, 106°33´E), 2 m, 0 8.05.1915, collector unknown (mor: 1 LIN 851 " Pallasea (Pallasea) baicali inermis , det. Dorogostaisky");

Off Posolskoe, southern edge of Selenga delta (S), 52°01´N, 106°10´E (st. 99-6), 3.5 m, sand, 21.7.1999, coll. RV & RMK (mor: 1; mtD: 1)

Type locality. Lake Baikal, Kultuk Bay (southern basin; as specified in Kamaltynov 2002).

Diagnosis. Marginal prominences of head about equal in length to marginal prominences of pereonite 1 ( Fig. 4 b). Uronite 1 with dorso-lateral setae only ( Fig. 4 c). Antenna 1 shorter than or equal to a half of body length ( Fig. 4 a). Antenna 1 peduncle segment 1 1.1–1.2 times as long as segment 2, and segment 2 1.5 times as long as segment 3 ( Fig. 4 a, 5a). Mandibular palp segment 1 without setae; segment 3 with 16 to 22 short ventral spine-setae ( Fig. 5 b). Coxa 4 with straight distal margin ( Fig. 4 a). Posterior margin of pereopod 6 basis slightly concave ( Fig. 6 c). Uropod 3 shorter than urosome ( Fig. 4 a), rather wide. Uropod 3 exopod 1.3–1.5 times as long as endopod (difference in the length especially strong in younger specimens) ( Fig. 7 a).

Color white, greenish-white or yellowish-white; spots varying in color from slight greenish-brown, yellowish or reddish to dark red or black, varying with the size of animal and substrate (environment). Pereonites 1−5 all with narrow dorso-lateral spots ( Fig. 3 a, b).

Body length of mature individuals 21–33 mm.

Description of lectotype. Fitting the generic and specific diagnoses above, with following specifications: Marginal prominences of head conical, sharp. Uronite 2 with two dorso-lateral spine-setae. Uronite 3 with three dorso-lateral spine-setae. Antenna 1 length 0.43 of body length. Antenna 1 about 1.5 times as long as antenna 2. Flagellum with 26 subsegments. Length of antenna 2 peduncle segment 4 equal to segment 5 length. Mandibular palp segment 3 with 16 short ventral spine-setae. Uropod 3 exopod 1.3 times as long as endopod.

DNA. Mitochondrial DNA typified by the sequence of a fragment of the COI deposited in GenBank with accession no GQ919203 (from a specimen from Kultuk Bay, MZH 53175), from which conspecific specimens differ at less than 10 % of nucleotide sites, whereas any heterospecific sequences studied differed at more than 15 %. The variability within B. baikali comprises four main lineages, with typical geographical distributions: southern, eastern, western (around Olkhon Island), and northern (represented by GenBank sequences GQ919203 - GQ919206 ). ( Figs 1 a and 2).

Allozymes. Distinguished from B. nigromaculatus by having electrophoretically faster allozymes of the enzymes ENO, MDH-1 and PGD, and electrophoretically slower ones of the enzymes AAT-2, AP, ARK, IDH- 1, IDH-2, MDH-2 and PGM (Table 1).

Distribution and habitat. Throughout the coasts of Baikal ( Fig. 1 a), on shallow-water sandy bottoms. Depth 0.5–30 m, more often less than 10 m.

Figures

FIGURE 1. Distributions of (a) Babr baikali (Stebbing, 1899) and (b) B. nigromaculatus (Dorogostaisky, 1922), based on the samples examined (molecular and morphological data). The map shows the 500 - m isobaths of Lake Baikal indicating the three main sub-basins N, C and S.

FIGURE 3. Babr baikali (Stebbing, 1899): (a) specimen from Kultuk Bay (type locality), 14.8. 2007, 30 mm, lateral view; (b) specimen from Khul Bay, 23.9. 2000 (stored frozen), 30 mm, dorsal view.

FIGURE 4. Babr baikali (Stebbing, 1899), lectotype: (a) total body, lateral view (setae not shown); (b) anterior part of body, dorsal view; (c) urosoma, lateral view. Scale bars 1 mm.

FIGURE 5. Babr baikali (Stebbing, 1899), (a) specimen from Davsha Bay, (b), (c), (d) lectotype: (a) head with antennula and antenna, lateral view; (b) mandibular palp, medial view; (c) maxilla 2, medial view; (d) left maxilla 1; right maxilla 1. Scale bars 1 mm.

FIGURE 6. Babr baikali (Stebbing, 1899), lectotype: (a) gnathopod 1, lateral view; (b) pereopod 5, lateral view; (c) basis and ischium of pereopod 6, lateral view; (d) basis, ischium and merus of pereopod 7, lateral view; (e) carpus, propodus and dactylus of pereopod 7, medial view. Scale bars 1 mm.

FIGURE 7. Babr baikali (Stebbing, 1899), lectotype: (a) uropod 3, dorsal view; (b) telson, dorsal view. Scale bars 1 mm.