Two new species of shrimp gobiid, Amblyeleotris (Teleostei: Gobiidae), from the West Pacific

Two new species of shrimp goby, genus Amblyeleotris Bleeker, 1852, are described herein from the West Pacific. Amblyeleotris bleekeri, collected from Taiwan, is distinguished from all congeners by the unique combination of the following features: (1) D1VI; D2 I/13; A. I/14; P 19; LR 62–63; (2) V with very low connecting membrane and lacking frenum; and (3) colouration: head and body of pale white background with five brown bands; interspaces of bands with 111‐shaped brown marks; a longitudinal blackish‐brown stripe behind orbit and a dark spot behind upper lip. Amblyeleotris taipinensis, collected from the South China Sea, is distinguished from all congeners by the unique combination of the following features: (1) D1VI; D2 I/13; A I/14; P 19, LR 73–76; (2) V with very low connecting membrane and lacking frenum; and (3) colouration: snow white body with six straw yellow bands and dorsal side with two rows of tiny black spots.


Introduction
The slender shrimp gobiid genus, Amblyeleotris Bleeker, 1852, which represents the association between shrimp in coral reef regions, is widely distributed in the Indo-Pacific region. This genus was found to have abbreviated transverse infraorbital sensory papillae (Akihito et al. 1993(Akihito et al. , 2002 and rather abbreviated, paired row f below the lower jaw (Polunin and Lubbock 1977;Miller, pers. comm.). At least 26 nominal species were validated by 2000 (Aonuma and Yoshino 1996;Mohlmann and Munday 1999;Aonuma et al. 2000). However, Randall (1995) listed Amblyeleotris exilis (Smith, 1958) as a junior synonym for Amblyeleotris periophthalma (Bleeker, 1853). More recently, several species were identified and described from the central and west Pacific; before our present study, there were at least 33 valid species within the genus (Mohlmann and Randall 2002;Randall 2004;Randall and Earle 2006).
During a survey of marine fish biodiversity in Taiwanese waters and the South China Sea in 1991-1995, we revised our collections of shrimp gobies, Amblyeleotris Bleeker, revealing eight previously validated species with seven new records from Taiwanese waters (Chen et al. 1998). Herein, we report and describe two undescribed species of Amblyeleotris from northern Taiwan and South China Sea based on our survey of the marine fish fauna. The total count for valid species of the genus in the Indo-Pacific is up to 35. An artificial key to all species of this genus is provided here.

Materials and methods
Measurements follow Miller (1988) and counts follow Chen and Shao (1996), Chen et al. (1999), and Chen and Kottelat (2005). Terminology of cephalic sensory canals and free neuromast organs (sensory papillae) is from Miller (1988) and Wongrat and Miller (1991), based on Sanzo (1911). Vertebral count is based on X-ray radiographs. The length of connecting membrane relative to fifth pelvic fin rays as a CM value follows Aonuma and Yoshino (1996) which is based on the UM value of Yanagisawa (1976 covered with rather small cycloid scales. Midline of nape naked. Scales on sides extend forward approximately to the midline edge of the opercle. Scales absent on opercle, cheek and pectoral fin base. Head lateral-line system ( Figure 1A). Canals: anterior oculoscapular canal with paired terminal pore s, single pore l and single pore k on interorbital region, paired v behind orbit; and paired lateral side of canals with pores a, b, and terminal pores r. Posterior oculoscapular canal with two terminal pores h and t. Preopercular canal with pores c, d and e.
Other papillae shown in detail in Figure 1.
Colouration in life ( Figure 2). Head and body of pale white background with five brown bands, which are deeper in middle region. The first band on the opercle; the second one below first dorsal fin base; the third band and fourth one under second dorsal fin base; fifth band on caudal peduncle. Dorsal side with a series of eight brown spots from nape to caudal fin base, each composed of two separated, symmetrical spots along both sides of two dorsal fin bases. The interspaces between lateral brown bands consist of three vertical brown lines forming a 111-shape; the middle row shorter and somewhat zigzagged, and shorter than anterior and posterior rows. A row of round brown spots from upper gill opening to caudal fin; the first shoulder spot seems to be more conspicuous than the remaining brown spots on the 111-shaped line just above longitudinal midline on body. Dorsal half of body light pale brown. Two greyish-brown marks on inter-orbital side of eyeballs.
Cheek with several light blue spots, a conspicuous, thin longitudinal blackishbrown stripe behind orbit extending along lateral region of oculoscapular canal to upper gill opening. Opercle with a deep brown mark in upper half. A round deep brown spot just behind upper lip. Snout with a pair of brown spots. First dorsal fin with several oblique rows of light yellow stripes with alternative pale stripes. Second dorsal base with a very light greyish-purple band with about 35 round yellow spots arranged as two to three rows. Pectoral fin pale white and pectoral fin base with a vertical orange stripe and a conspicuous deep brown spot on upper region. Anal fin white and distal region purple grey with two to three light yellow spots. Caudal fin translucent with a C-shaped brown mark. Pelvic fin light greyish-yellow.

Distribution
This new species has only been found in the coastal regions off northeastern Taiwan and the Penghu islands.

Etymology
The new species is named after the famous Dutch ichthyologist, Dr. P. Bleeker who has made significant contributions to Indo-Pacific fish research and also created this marine gobiid genus Ambyeleotris.

Remarks
The new species is more similar to the Japanese species Amblyeleotris masuii Aunoma and Yoshino, 1996 than to any other congener by overall colouration pattern. However, Amblyeleotris bleekeri is well distinguished from Amblyeleotris masuii by the following combination of features: (1)  (2) pelvic fin: frenum absent versus frenum present; (3) fin colouration: D2 with thin distal brown margin and no shiny spots on D2 and C versus a conspicuous red margin or rows of small red spots on D2 and C. Amblyeleotris bleekeri also shares similarities in some colouration patterns as well as dorsal and anal fin rays counts with Amblyeleotris triguttata Randall, 1994. Amblyeleotris bleekeri is easily distinguished from Amblyeleotris triguttata as Description. Body proportions in Table I. Head and body moderately compressed. Eyes large. Mouth large and oblique, maxillary extending to vertical of posterior margin of pupil. Lower jaws with three to four rows of subconical teeth; outer rows elongated and separated. Inner teeth inwardly curved, one to two large canines. Snout is rather blunt, shorter than orbit. Bony interorbital is very narrow. Gill opening extending forward below posterior margin of orbit. Anterior nostril a short tube. Posterior nostril a round hole. Opercle and preopercle edges smooth. Isthmus narrow. 10+16526 vertebrae. Fins. D1VI; D2 I/13; A I/14; P 19; V I/5. D1 II, III longest, extending to first branched ray of D2 when depressed. D2 base and A base long, rear tips just reaching the upper procurrent rays of C. A origin inserted below first branched rays of D2. P large, extending almost to the edge of anus. C lanceolate. V rather long, extending beyond the origin of A and fourth branched rays longest; the connecting membrane very low, less than 1/10. No frenum.
Scales. Body with very tiny cycloid scales anteriorly, and ctenoid scales posteriorly. Longitudinal scale rows 73-76; transverse scale rows 28; predorsal scale 0. Ventral body covered with rather tiny cycloid scales. Midline of nape naked. Scales on sides extending forward above opercle. Scales absent on opercle, cheek and pectoral fin base.
Head lateral-line system ( Figure 1B). Canals: anterior oculoscapular canal with paired terminal pore s, single pore l and single pore k on interorbital region, paired v behind orbit; and paired lateral side of canals with pores a, b, and terminal pores r. Posterior oculoscapular canal with two terminal pores h and t. Preopercular canal with pores c, d, and e.
Colouration in life. Colouration based on the unique holotype ( Figure 3). Head and body snow white, body with five wide, vertical light straw-yellow bands. Nape entirely straw yellow. The band on head narrower, below orbit on cheek extending to lip corner. The first wide dorsal band from nape to opercle. Second band just below first dorsal fin base. Third band on anterior region below second dorsal fin and fourth band below posterior region of second dorsal fin. Fifth band on caudal fin peduncle. No distinct spots on cheek. A pair of brownish-black spots along first dorsal fin base; two rows of brownish-black spots behind first dorsal fin base to caudal peduncle along dorsal midline, first row with three on upper side near dorsal fin bases, second row with four such spots just below first row. First dorsal and second dorsal fins with two thin, longitudinal rows of greyish-purple stripes on basal region, and a pink longitudinal midline between them. Pectoral fin base with a narrow vertical straw yellow band. Caudal fin translucent and somewhat straw yellow in middle rays.

Distribution
So far, this new species has only been found near Nansa Isles: Taipin Island (also referred to Spratly Island) in the South China Sea.

Etymology
The specific name, taipinensis refers to the locality at which the species was found, Nansa Isles, Taipin Island, in southern region of the South China Sea.

Remarks
This species is more similar to Amblyeleotris arcupinna than any other congeneric species by the colour pattern, both with five dark bands on the body and a series of semi-paired dots in the white interspaces along dorsal body.    (Klausewitz, 1969)