Automate hayashii, Anker & Komai, 2004
|
publication ID |
https://doi.org/ 10.1080/0022293031000156312 |
|
persistent identifier |
https://treatment.plazi.org/id/03CC87D5-FFF2-FFF4-7390-FD46FE54FBCE |
|
treatment provided by |
Carolina |
|
scientific name |
Automate hayashii |
| status |
sp. nov. |
Genus Automate De Man, 1888 View in CoL Automate hayashii sp. nov. ( figures 1–4 View FIG View FIG View FIG View FIG )
Material examined. HOLOTYPE: non-ovigerous female (CL 8.5 mm, TL 26.0 mm), CBM-ZC 6559, tidal flat at Kamiiso , Hakodate Bay, southern Hokkaido, Japan, intertidal, 16 May 1991, S. Goshima coll.
Description. Carapace glabrous. Frontal region with very shallow orbital concavities on either side of very short, broad rostrum; rostrum distally rounded, reaching to level of antero-lateral margin of carapace, covering only medio-basal portion of eye-stalks ( figure 2A View FIG ); rostral carina and orbital teeth absent. Eyestalks exposed dorsally and laterally ( figure 2B, C View FIG ), mesial margins nearly parallel and mesially almost touching; cornea moderately developed, lateral ( figure 2B View FIG ). Pterygostomian angle rounded, continuous with branchiostegal margin ( figures 1 View FIG , 2C View FIG ); cardiac notch conspicuous ( figure 1 View FIG ).
Antennular peduncle with second segment somewhat longer than visible portion of first segment; dorso-mesial margin of first segment with a row of two or three small, somewhat anteriorly curved spines ( figure 2B View FIG ); stylocerite acute, short, not appressed, exceeding distal margin of first segment ( figure 2A View FIG ); ventro-mesial carina on first segment terminating anteriorly in acute tooth (shown under stylocerite in figure 2C View FIG ); outer flagellum not subdivided, aesthetasc-bearing portion moderately thickened. Antenna with basicerite bearing strong ventro-lateral tooth; carpocerite slender, reaching far beyond scaphocerite and exceeding distal margin of antennular peduncle ( figure 2C View FIG ); scaphocerite oval ( figure 2D View FIG ), slightly falling short of distal end of second segment of antennular peduncle, lateral margin nearly straight, distolateral tooth strong, not reaching bluntly angular anterior margin of blade.
Mouthparts not dissected (except second maxilliped), nevertheless appearing to be quite typical for Alpheidae . Second maxilliped without podobranch. Third maxilliped slender, over-reaching distal end of scaphocerite by full length of ultimate segment; ultimate segment armed with row of strong spines along superior margin ( figure 2C View FIG ); lateral plate on coxa inconspicuous; strap-like epipod and single arthrobranch present.
First pereopods (chelipeds) robust and strongly asymmetrical ( figures 1 View FIG , 3 View FIG A–D). Major cheliped ( figure 3A View FIG ) with ischium unarmed; merus very stout, somewhat thickened in central portion, margins not rugose; carpus robust, cup-shaped, slightly elongated; chela somewhat compressed laterally; palm oval-shaped, slightly constricted at base; fingers in strongly oblique position to main palm axis; pollex short, robust, with one basal, triangular tooth followed by a large truncated central molar-shaped tooth and subdistal hiatus on cutting edge ( figure 3B View FIG ); dactylus robust, much shorter than full palm length, slightly curved, cutting edge armed with one low tooth fitting into space between basal and central tubercles of pollex ( figure 3B View FIG ); tips of fingers crossing. Minor cheliped ( figure 3C, D View FIG ) also stout, but merus and carpus more slender compared to major cheliped; superior margin of ischium distally armed with one spine ( figure 3C View FIG ); chela much less inflated, more slender than chela of major cheliped, constricted at base; fingers slightly shorter than palm, only slightly curved, sub-parallel to main palm axis, unarmed on cutting edge, tips crossing.
Second pereopod ( figure 3E View FIG ) slender, elongated, reaching to or even beyond the tip of the third maxilliped when fully extended; carpus five-articulated, second article longer than first, ratio of articles from proximal to distal approximately equal to 1:1.3:0.6:0.4:0.6. Third pereopod ( figure 3F View FIG ) robust, laterally compressed; ischium armed with one ventral spine; merus unarmed; carpus armed with one slender disto-ventral spine; propodus armed with five or six spines; dactylus robust, somewhat compressed laterally, slightly curved, tip subacute ( figure 3F View FIG ). Fourth pereopod similar to third pereopod (cf. figure 1 View FIG ). Fifth pereopod much more slender than third and fourth, but otherwise similar (cf. figure 1 View FIG ); propodus armed with two spines; propodal grooming brush well developed ( figure 3G View FIG ).
Abdomen with pleura of first to fifth somites rounded ventrally and covering only most basal portions of coxae of pleopods ( figure 1 View FIG ); sixth segment without distinct articulated flap, postero-lateral projection rounded ( figure 2E View FIG ); preanal plate posteriorly rounded. Telson ( figure 2F View FIG ) broad at base, slightly tapering distally, with two pairs of dorso-lateral spines, first and second pair situated at about half and posterior three-quarters of telson length, respectively ( figure 2F View FIG ); posterior margin slightly convex, with two pairs of slender spines at lateral corner (inner spine about three times longer than outer spine) and numerous (dozen) setae between spines; anal tubercles absent.
Second pleopod bearing only appendix interna and a few elongated setae ( figure 3H View FIG ). Uropod distinctly exceeding telson ( figure 2E View FIG ); endopod somewhat longer than exopod; exopod with two posterior projections bordering a shallow cleft on diaeresis ( figure 2E View FIG ), postero-lateral corner only weakly produced and subacute, accompanied with rather stout spine arising just mesial to it.
Gill formula typical for Alpheidae : pleurobranchs on fourth to eighth thoracic somites (above third to fifth pereopod); one arthrobranch above third maxilliped; strap-like epipods (mastigobranchs) on first maxilliped to fourth pereopods; setobranchs on first to fifth pereopod.
Colour in life. Uniform light orange.
Size. Fairly large Automate species, attaining 8.5 mm in CL, 25.0 mm in TL.
Distribution and habitat. Presently known only from Hakodate Bay, Hokkaido, Japan, where the holotype was collected intertidally. The new species is the northern-most species of Automate , and one of the northern-most alpheid shrimps in the Pacific Ocean. In Japan, it is the only species of Automate reported from Hokkaido. Another species known from Japan, A. dolichognatha , is known only from warm temperate to subtropical waters from Sagami Bay southward to the Ryukyu Islands ( Miyake and Miya, 1966; Hayashi, 1995; Nomura et al., 1998; Nomura and Asakura, 1998).
Etymology. This new species is named in honour of our dear colleague Dr Ken-Ichi Hayashi (National Fisheries University, Shimonoseki, Japan), who contributed so much to the taxonomic and biological knowledge of shrimps in Japan and elsewhere in the world.
Discussion. The genus Automate was established by De Man (1888) for A. dolichognatha De Man, 1888 , described from Pulau Tuguan, Indonesia. Although 12 species have been described in the genus, four nominal species were reduced to synonyms of A. dolichognatha , which is presently considered to be a highly variable, almost pantropical species ( Chace, 1972, 1988; Banner and Banner, 1973). These are: A. gardineri Coutière, 1902 (type-locality: Maldive atolls, Gilbert Islands, Masqat and Djibouti); A. kingsleyi Hay, 1917 (type-locality: Beaufort, North Carolina); A. haightae Boone, 1931 (type-locality: Taboguilla, Gulf of Panama) and A. johnsoni Chace, 1955 (type-locality: Bikini Atoll, Marshall Islands). At present, the following seven species are recognized as valid other than the type species, A. dolichognatha (pantropical, cf. Chace, 1988): A. evermanni Rathbun, 1901 (western Atlantic: from North Carolina to southern Brazil; eastern Atlantic: Gulf of Guinea); A. talismani Coutière, 1902 (known only from Cape Verde Islands); A. rugosa Coutière, 1902 (Pacific coast of Mexico south to Panama), A. salomoni Coutière, 1908 (known only from the type-locality, Salomon Island, Chagos Archipelago); A. anacanthopus De Man, 1910 (Indo-West Pacific: Hong Kong, Vietnam, Indonesia, Papua New Guinea and Madagascar); A. branchialis Holthuis and Gottlieb, 1958 (Mediterranean Sea: France, Croatia, Israel); and A. rectifrons Chace, 1972 (Caribbean Sea: Quintana Roo, Mexico, and possibly Antigua Island) (e.g. Rathbun, 1901; Coutière, 1902, 1908; De Man, 1911; Holthuis, 1951; Holthuis and Gottlieb, 1958; Ledoyer, 1970; Chace, 1972, 1888; Banner and Banner, 1973; Wicksten, 1981; Dworschak and Coelho, 1999). Chace (1988) remarked that the true identity of A. talismani remains unclear, but in the absence of more data he preferred to treat it as a distinct species, as did Banner and Banner (1973).
We are not fully convinced by the synonymies proposed by the previous authors, as recent studies have revealed the existence of many sibling or cryptic species in Alpheidae (e.g. Knowlton and Keller, 1983, 1985; Knowlton and Mills, 1992; Williams et al., 1999; Anker, 2000, 2001a). Although a thorough review of the genus Automate is beyond the scope of this paper, we would like to suggest that at least A. gardineri and A. johnsoni might be valid and would need to be resurrected. The generic assignment of A. salomoni and A. talismani remains not fully confirmed, as these two species are represented by one damaged holotype of unknown sex and two apparently lost syntypes, respectively. Wicksten (1999) recommended a comparison between Coronalpheus natator Wicksten, 1999 and the above-mentioned two species of Automate .
The present new species is assigned to Automate on account of the following features ( De Man, 1888; Chace, 1988; Holthuis, 1993): the sixth abdominal somite lacks an articulated plate at the postero-lateral angle; the eye-stalks are juxtaposed and fully exposed in the dorsal view; at least the anterior two pairs of pereopods bear a strap-like epipod. Within Automate , A. hayashii sp. nov. appears to be closest to the poorly known A. salomoni . Coutière’s (1908) original description of A. salomoni was not accompanied by illustrations, but subsequently he ( Coutière, 1921) published somewhat diagrammatic figures of this species. To ascertain the affinities and differences between the two species, the holotype of A. salomoni deposited in the MNHN has been re-examined. The holotype is lacking most of its thoracic appendages, including chelipeds. Beside the lack of the appendages, however, the specimen was in reasonably good condition ( figure 4 View FIG ). The similarities between the two species are confirmed: they share indeed several important characters, such as the clearly formed, broad rostrum, the uropodal endopod being longer than the exopod, and the ventro-mesial carina on the basal segment of the antennular peduncle produced anteriorly in a small acute tooth. Nevertheless, Automate hayashii sp. nov. is specifically distinct from A. salomoni , differing in the broadly rounded and shorter rostrum (compare figures 2A View FIG and 4C View FIG ) and the more robust third pereopod (compare figures 3F View FIG and 4E View FIG ). Further, the disto-lateral spine of the scaphocerite does not exceed the anterior margin of the blade in A. hayashii sp. nov. ( figure 2D View FIG ), rather than distinctly over-reaching it, as is the case in A. salomoni ( figure 4C View FIG ).
| MNHN |
Museum National d'Histoire Naturelle |
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.