KURENAI : Kyoto University Research Information Repository Four Species of the Genus Grandidierella (Crustacea : Title Amphipoda : Aoridae) from Osaka Bay and the Northern Part of the Kii Channel, Central Japan Author(s) Ariyama, Hiroyuki PUBLICATIONS OF THE SETO MARINE BIOLOGICAL Citation LABORATORY (1996), 37(1-2): 167-191 Issue Date 1996-02-29 URL http://hdl.handle.net/2433/176253 Right Type Departmental Bulletin Paper Textversion publisher Kyoto University Pub!. Seto Mar. Bioi. Lab., 37(1/2): 167-191, 1996 167 Four Species of the Genus Grandidierella (Crustacea: Amphipoda: Aoridae) from Osaka Bay and the Northern Part of the Kii Channel, Central Japan HIROYUKI ARIYA MA Osaka Prefectural Fisheries Experimental Station, Tanagawa, Misaki, Osaka 599-03, Japan Abstract Four species of the genus Grandidierella were collected from estuaries and coastal area in Osaka Bay and the northern part of the Kii Channel, central Japan. Grandidierella fasciata sp. nov., G. osakaensis sp. nov. and G. japonica Stephensen, 1938 were from brackish area, G. insulae Myers, 1981 from sea area. These amphipods are described and validness of the three brackish species is examined by crossing experi ments. Key words : Amphipoda, Aoridae, Grandidierella, Osaka Bay, Kii Channel, crossing experiments Introduction The genus Grandidierella Coutiere, 1904 contains 33 species to date. Prior to 1986, 31 species were recorded (Barnard & Karaman, 1991). After then two species, G. taihuensis Morino & Dai, 1990 and G. nagadae Myers, 1995, were described_ So far in I a pan only Grandidierella japonica Stephensen, 1938 represents this genus (Ishimaru, 1994). I have been investigating amphipod fauna of the coastal area and estuaries in Osaka Bay and the northern part of the Kii Channel since 1981. During this survey four Grandidierella species were collected, and two of them have turned to be new species. Present paper deals with descriptions of all these species and a result of crossing experiments among three brackish species. The dissected specimens including the type series are deposited in the Osaka Museum of Natural History (OMNH). Descriptions Grandidierella fasciata sp. nov. (Japanese name: shima-dorosokoebi, new) (Figs. 1-5) Material examined. Holotype: male (OMNH-Ar-3840), 8.4 mm, intertidal zone at the mouth of the Higashi-kawa (Ochiai-gawa) River in Misaki, Osaka Prefecture (34"19'N, 135"07'E), brackish water, sandy mud bottom mixed with gravel, 20 Feb. 1992, collected by the author. Allotype : female (OMNH-Ar-3841), 6.5 mm, the same data as the holotype_ Paratypes: 1 male (OMNH Ar-3842), 7.4 mm and 1 female (OMNH-Ar-3843), 6.7 mm, 6 Feb.1989; 1 male (OMNH-Ar-3844), 7.7 mm and 1 ovigerous female (OMNH-Ar-3845), 10.1 mm, 7 Jun. 1990; 1 male (OMNH-Ar- 3846), 8.2 mm, 4 May 1991, the same place as the holotype, collected by the author. Besides the type series the specimens from following localities were examined (undissected) : 68 individuals from pebble beach of Hakotsukuri in Han'nan, Osaka Pref.; 10 from the mouth of the Tayama gawa River in Han'nan, Osaka Pref.; 28 from the mouth of the Oh-kawa River in Misaki, Osaka Pref.; hundreds from the mouth of the Higashi-kawa River in Misaki, Osaka Pref.; 3 from the estuary of the Ki-no-kawa River in Wakayama Pref. Male (holotype) Body (Fig_ 1) : Subcylindrical ; rostrum indistinct ; eyes oval, medium m size ; pereon 168 HIROYUKJ ARIYAMA Fig. 1. Grandidierella fasciata sp. nov. Male (holotype). segments lacking ventral process; epimeral plates 1-3 (Fig. 3-C), with. a spine on ventropos terior corner, plate 2 with a plumose seta ventrally. Antenna 1 (Fig. 3-A) : Ratio of peduncular articles 1-3 2.8: 3.1 : 1, article 1 robust, inner surfaces of articles 1-2 (Fig. 3-A1) with 3 and 2 spines, respectively; primary flagellum with 20 articles, 1.3 times as long as peduncle;accessory flagellum (Fig. 3-A2) uni-articulate, short. Antenna 2 (Fig. 3-B) : Peduncle stout, inner surfaces of articles 3-4 (Fig. 3-B1) with 5 and 4 spines, respectively, article 5 somewhat longer than article 4; flagellum short, with 7 articles, flagellar articles 4-7 (Fig. 3-B2) with 1, 1, 1, 2 curved spines, respectively. Mouth parts: Upper lip (Fig. 4-E) subrounded ventrally without depression; lower lip (Fig. 4-F), ventral part of outer lobe covered with thin hairs, inner lobe incised; mandible (Fig. 4-D), palp article ratios 1: 1.5: 1.4; maxillaJ1 (Fig. 4-C), outer plate with 10 apical spines, palp article 2 with 6 apical spines ; maxilla 2 (Fig. 4-B), medial margin of inner plate with an oblique row of setae ; maxilliped (Fig. 4-A), inner plate with 2 oblong spines, outer plate with 13 marginal spines, ratio of palp articles 1-4 1: 1.7: 1.1: 0.6. Coxal plates (Fig. 2): Plates 1-4 subrectangular; plates 5-7, posterior half shallower than anterior one ; plate 1 largest. Gnathopod 1 (Fig. 2-A): Large, complexly subchelate; article 2 wide, about 1.7 times as long as broad, posterior margin rounded with several setae; article 3 short; article 4 rectangular, posterodistal angle with an acute projection; article 5 subovoid, about 1.5 times as long as broad, posterior margin with three teeth, two large and one small ; article 6, about half length of article 5, posterior margin expanded distally ; dactyl medially weakly expand ed. Gnathopod 2 (Fig. 2-B): Slender, subchelate; article 2 elongate, slightly dilated distally; article 4 trapezoidal, distal margin setose ; article 5 expanded medially, posterior margin FOUR SPECIES OF GRANDIDIERELLA FROM OSAKA BAY 169 0.2 mm :A, B,C, D, L-...J E,F,G 0.2mm:B1 Fig. 2. Grandidierella fasciata sp. nov. Male (holotype) : A, gnathopod 1 ; B, gnathopod 2 ; Bl, palm and dactyl of gnathopod 2; C-G, pereopods 3-7. 170 HIROYUKI ARIYAMA A2 0.2mm:A,B L_l 0.2mm:A1,B1,C,E, [____J F,G,H,l,J 0.2mm:D 0.2mm: A2, 82 81 Fig. 3. Grandidierella fasciata sp. nov. Male (holotype) : A, antenna 1 ; A1, peduncular articles 1-2 of antenna 1 (inner view) ; A2, accessory flagellum; B, antenna 2 ; B1, peduncular articles 3-4 of antenna 2 (inner view); B2, flagellum of antenna 2; C, epimeral plates 1-3; D, telson (lateral view) ; E-G, pleopods 1-3 ; H-], uropods 1-3. FOUR SPECIES OF GRANDIDIERELLA FROM OSAKA BAY 171 setose ; article 6 ovoid, about two thirds length of article 5, palm almost transverse, defined by a pair of spines, posterior margin with 2 spines (Fig. 2-B1) ; dactyl unguiform, inner margin minutely serrate. Pereopods 3-4 (Figs. 2-C,D) similar to each other, dactyl about 0.6 times as long as article 6; pereopod 5 (Fig. 2-E), article 2 posterodorsally produced, with a plumose seta posteriorly, articles 5-6 with a row of marginal spines; pereopods 6-7 (Figs. 2-F,G) similar to each other, elongate, 1.6 times as long as pereopod 5, article 2 with long plumose setae, several on anterior margin and numerous on posterior margin, posterodistal corner of article 4 with a spine, articles 5-6 with a row of marginal spines. Pleopods 1-2 (Figs. 3-E,F) longer than pleopod 3 (Fig. 3-G); peduncles with long plumose setae and 2 coupling spines, outer ramus shorter than inner. Uropods (Figs. 3-H,I,J) : Peduncles of uropods 1-2 longer than respective rami, dorsal surfaces of peduncles and of both rami spinous, distal end of uropod 1 peduncle with a inter-ramal process; uropod 3, peduncle a little shorter than ramus, peduncle inner margin strongly expanded, ramus with tiny second article and 11 long setae. Telson (Fig. 3-D): Rectangular in lateral view, with several setae on dorsolateral margins. Female (allotype) Similar to male except the following respects. Gnathopod 1 (Figs. 4-I,Il): Smaller than that of male, subchelate; article 2 about 1.9 times as long as broad; article 4 trapezoidal without projection; article 5 subovoid, about 1.8 times as long as broad, posterior margin with setae and two spines ; article 6 pyriform, a little shorter than article 5, palm oblique and defined by 3 spines, posterior margin with 2 spines ; dactyl claw-like, inner margin minutely serrate. Gnathopod 2 (Figs. 4-J,Jl): Similar to that of male, but article 2 broadened medially and article 6 rectangular, about 0.8 times as long as article 5, palm transverse, defined by three spines. Coloration in life Eyes black ; head, pereonites 4 and 7 dark brown, other pereonites and pleonites pale yellow, body patterned with stripes as a whole ; antennae orange ; other appendages whitish, article 6 of pereopods 3-4 with a red vermiform spot and article 6 of male gnathopod 2 (and sometimes male gnathopod 1) with a red small dot. Remarks This new species is very close to Grandidierella dentimera Myers, 1970 from Hawaii in male gnathopod 1 which has three teeth on article 5 and a projection on article 4. But Grandidierella fasciata differs from G. dentimera in the shape of article 6 of male gnathopod 1, shorter articles 5-6 of male gnathopod 2 and shorter inner lobe of lower lip. Grandidierella fasciata also resembles G. bonnieroides Stephensen, 1948, G. lignorum K.H. Barnard, 1935, G. palama J.L. Barnard, 1977 and G. robusta Ledoyer, 1982 in the presence of three teeth on article 5 of male gnathopod 1. However, this new species can be clearly distinguished from the latter 4 species by the presence of a projection on article 4 of male gnathopod 1. Ecology This species occurs in the middle-lower intertidal zone of the sandy mud bottom or under stones at river mouths. Females were observed brooding from March to June (July-January were not examined). Distribution From Hakotsukuri in Han'nan, Osaka Prefecture to the estuary of the Ki-no-kawa River 172 HIROYUKI ARIYAMA E~\ G ~:D,G,H,I,J ,0.2mm:A E,F 1 0.2mm:B,C,11,J1 Fig. 4. Grandidierella fasciata sp. nov. Male (holotype) : A, maxilliped ; B, maxilla 2 ; C, maxilla 1 ; D, mandible; E, upper lip ; F, lower lip. Female (allotype) : G, peduncular articles 1-2 of antenna 1 (inner view) ; H, peduncular articles 3-4 of antenna 2 (inner view) ; I, gnathopod 1 ; Il, palm and dactyl of gnathopod 1; ], gnathopod 2 (oostegite omitted); Jl, palm and dactyl of gnathopod 2. FOUR SPECIES OF GRANDIDIERELLA FROM OSAKA BAY 173 135°E 135°20'E Muko R. KOBE~,) .,C- ~f__ ~o"0Yodo R. 34"40'N AKASHI Harima Nada SAKAl Osaka Bay Awaji Is. Onosato R. 34°20'N HAN'NAN 0 10 20km ======~ Kii Channel Fig. 5. Distribution of Grandidierella fasciata sp. nov. Square shows the type locality. in W akayama Prefecture (Fig. 5). Grandidierella osakaensis sp. nov. (Japanese name: ohsaka-dorosokoebi, new) (Figs. 6-10) Material examined. Holotype: male (OMNH-Ar-3855), 6.9 mm, intertidal zone at the mouth of the Yodo-gawa River in Osaka (34° 41'N, 135"25'E), brackish water, the sandy mud bottom mixed with gravel, 11 May 1991, collected by the author. Allotype: female (OMNH-Ar-3856), 7.1 mm, the same data as the holotype. Paratypes: 1 male (OMNH-Ar-3857), 6.1 mm, the same data as the holotype; 1 male (OMNH-Ar-3858), 7.5 mm, and 1 female (OMNH-Ar-3859), 6.9 mm, intertidal zone at the mouth of the Higashi-kawa River in Misaki, Osaka Pref., brackish water, the sandy mud bottom mixed with gravel, 20 Feb. 1992, collected by the author. Besides the type series the 174 HIROYUKI ARIYAMA specimens from following localities were examined : 175 individuals from the mouth of the Yodo-gawa River in Osaka; 49 from the mouth of the Oh-kawa River in Misaki, Osaka Pref., 102 from the mouth of the Higashi-kawa River in Misaki, Osaka Pref. Male (holotype) Body (Fig. 6) : Subcylindrical ; rostrum indistinct ; eyes oval, small ; inferior antennal sinus deep; pereon segments lacking ventral process; epimeral plates 1-3 (Fig. 8-C), with a spine on posteroventral corner, plate 2 with several setae ventrally. Antenna 1 (Fig. 8-A): Ratio of peduncular articles 1-3 2.3 : 2.9 : 1, ventral surfaces of articles 1-2 with 3 and 2 spines, respectively (Fig. 8-AI) ; primary flagellum with 21 articles, almost as long as peduncle; accessory flagellum (Fig. 8-A2) uni-articulate, short. Antenna 2 (Fig. 8-B) : Peduncle conspicuously robust, inner surfaces of articles 3-4 (Fig. 8-Bl) with 4 and 2 spines, respectively, article 5 as long as article 4 ; flagellum short, with 6 articles, articles 2-6 (Fig. 8-B2) with 1, 1, 1, 1, 2 curved spines, respectively. Mouth parts: Upper lip (Fig. 9-E) subrounded, with a projection dorsally; lower lip (Fig. 9-F), ventral part of outer lobe covered with thin hairs, inner lobe incised; mandible (Fig. 9 -D), palp article ratios 1: 1.4: 1.5; maxilla 1 (Fig. 9-C), outer plate with 8 apical spines (probably a few spines were lost), palp article 2 with 6 apical spines ; maxilla 2 (Fig. 9-B), medial margin of inner plate with a row of short setae ; maxilliped (Fig. 9-A), inner plate with 4 oblong spines, outer plate with 7 mar.:;inal spines, ratio of palp articles 1-4 1 : 1.7: 1.1 : 0.7. Coxal plates (Fig. 7) : Plates 1-4 subrectangular, plates 5-6 posterior half shallower than anterior one, phte 7 triangular, short; plate 5 largest. Gnathopod 1 (Fig. 7-A): Large, complexly subchelate; article 2 wide, about 1.7 times as long as broad, posterior margin rounded with several setae ; article 3 short, produced posterodistally ; article 4 longish rectangular, posterodistal end with an acute projection ; article 5 subovoid, about 1.6 times as long as broad, posterior margin with three teeth, two large and one small; article 6 rectangular, about half length of article 5, posterior margin Fig. 6. Grandidierella osakaensis sp. nov. Male (holotype). FOUR SPECIES OF GRANDIDIERELLA FROM OSAKA BAY 175 0.2mm:A,B,C,D,E, l__J F,F1,G 0.2mm: 81 Fig. 7. Grandidierella osakaensis sp. nov. Male (holotype): A, gnathopod 1 ; B, gnathopod 2; Bl, article 6 and dactyl of gnathopod 2; C-G, pereopods 3-7; Fl, gill of pereopod 6.