Pseudochromis erdmanni, Gill, Anthony C. & Allen, Gerald R., 2011

Gill, Anthony C. & Allen, Gerald R., 2011, Pseudochromis erdmanni, a new species of dottyback with medially placed palatine teeth from Indonesia (Teleostei: Perciformes: Pseudochromidae), Zootaxa 2924, pp. 57-62 : 58-61

Pseudochromis erdmanni new species

Erdmann’s Dottyback

Figures 1–3 , Table 1

Pseudochromis moorei [non Fowler 1931]. Kuiter and Tonozuka, 2001: 137, fig. C (colour photograph, northern Sulawesi); Kuiter and Debelius, 2006: 238, unnumbered fig. (same colour photograph as Kuiter & Tonozuka (2001), but locality clarified as Lembeh Strait, Sulawesi, Indonesia).

Holotype. NCIP 6344, 81.5 mm SL, Indonesia, North Maluku Province, Halmahera, Loloda Selatan, Pulau Taunalu (01°40.488’N 127°31.720’E), fringing reef, 66 m, clove oil, M.V. Erdmann, 15 April 2008.

Paratypes. NCIP 6345, 3: 48.7–66.1 mm SL, Indonesia, Papua Barat Province, Raja Ampat Islands, northwest Batanta Island (00°47.752’S 130°009’E), 42 m, clove oil, M.V. Erdmann, 20 March 2008; WAM P.32911-002, 2: 68.3–74.7 mm SL, Indonesia, Papua Barat Province, Raja Ampat Islands, west Batanta Island (00°47.100’S 130°29.963’E), 59 m, spear, M.V. Erdmann, 19 August 2007; AMS I.45740-001, 71.3 mm SL, Indonesia, Ambon Island, Tulehu harbour (03°34’S 128°19’E), 45 m, M.V. Erdmann, 14 March 2009; WAM P.33082-002, 71.3 mm SL, collected with AMS I.45740-001.

Diagnosis. A species of Pseudochromis with the following combination of characters: palatine tooth patches inserted medially behind vomerine tooth patch; large dark grey to black spot on posterodorsal corner of operculum; pale blue curved bar behind eye; and anal fin without broad dark distal stripe.

Description (based on eight specimens, 48.7–81.5 mm; data for all types followed, where variation was noted, by data for holotype in parentheses): Dorsal-fin rays III,25–27 (III,26), all or all but first (all) segmented rays branched; anal-fin rays III,13–14 (III,14), all segmented rays branched; pectoral-fin rays 17–19 (18/18); upper procurrent caudal-fin rays 6; lower procurrent caudal-fin rays 5–6 (5); total caudal-fin rays 27–28 (28); scales in lateral series 40–45 (43/43); anterior lateral-line scales 33–36 (35/35); anterior lateral line terminating beneath segmented dorsal-fin ray 19–21 (20/20); posterior lateral-line scales 5–9 + 0–2 (9 + 0/9 + 1); scales between lateral lines 3–4 (4/4); horizontal scale rows above anal-fin origin 13–16 + 1 + 3–4 = 17–20 (15 + 1 + 3/14 + 1 + 3); circumpeduncular scales 20; predorsal scales 17–21 (17); scales behind eye 3–4 (4); scales to preopercular angle 6–8 (8); gill rakers 5–6 + 11–12 = 16–18 (5 + 12); pseudobranch filaments 13–16 (15); circumorbital pores 26–35 (35/32); preopercular pores 12–14 (14/14); dentary pores 4; posterior interorbital pores 1–2 (1).

Lower lip varying from incomplete with weak symphyseal interruption to complete; dorsal and anal fins without scale sheaths, although sometimes with intermittent scales overlapping fin bases; predorsal scales extending anteriorly to point ranging from posterior AIO to mid AIO pores; opercle with 4–6 large, distinct serrations, sometimes with additional small serration below subopercle junction; teeth of outer ceratobranchial-1 gill rakers varying from well developed on distal tips of rakers only, to well-developed along most of raker lengths; anterior dorsal-fin pterygiophore formula S/S/S + 3/1 + 1/1/1 + 1*/1 (S/S/S + 3/1 + 1/1/1 + 1/1); dorsal-fin spines stout and pungent; anterior anal-fin pterygiophore formula 3/1 +1*/1/1/1 + 1 (3/1 + 1/1/1/1 + 1); anal-fin spines stout and pungent, second spine stouter than third; pelvic-fin spine stout and pungent; second segmented pelvic-fin ray longest; caudal fin emarginate to deeply emarginate (almost lunate); vertebrae 10 + 15–16 (10 + 16); epineurals 14–15 (15); epurals 3.

Upper jaw with 2–3 pairs of curved, enlarged caniniform teeth, and 4–6 (at symphysis) to 2–3 (on sides of jaw) inner rows of small conical teeth, outermost of rows of conical teeth much larger and more curved than inner rows; lower jaw with 2–3 pairs of curved, caniniform teeth, and 3–5 (at symphysis) to 1 (on sides of jaw) inner rows of small conical teeth, teeth on middle of jaw larger and curved; vomer with 2 rows of small conical teeth, forming chevron; palatine with 1–3 irregular rows of small conical teeth arranged in elongate patch, anterior tip of patch directed medially behind posterolateral arm of vomerine tooth patch; ectopterygoid edentate; tongue moderately pointed and edentate.

As percentage of SL: Head length 23.3–26.1 (24.9); orbit diameter 7.1–8.8 (7.2); snout length 6.0–7.0 (7.0); fleshy interorbital width 5.1–6.0 (5.8); bony interorbital width 4.1–4.9 (4.9); body width 12.3–13.9 (13.9); snout tip to posterior tip of retroarticular bone 15.1–16.6 (15.7); predorsal length 31.7–35.7 (33.1); prepelvic length 28.8– 32.5 (30.6); posterior tip of retroarticular bone to pelvic-fin origin 14.9–17.8 (17.8); dorsal-fin origin to pelvic-fin origin 27.8–32.6 (28.7); dorsal-fin origin to middle dorsal-fin ray 32.6–37.5 (36.1); dorsal-fin origin to anal-fin origin 41.7–44.4 (42.1); pelvic-fin origin to anal-fin origin 28.1–34.1 (28.1); middle dorsal-fin ray to dorsal-fin termination 24.6–26.3 (26.3); middle dorsal-fin ray to anal-fin origin 26.1–30.0 (26.4); anal-fin origin to dorsal-fin termination 34.3–36.0 (36.0); anal-fin base length 25.5–28.0 (27.4); dorsal-fin termination to anal-fin termination 16.3–17.3 (17.3); dorsal-fin termination to caudal peduncle dorsal edge 11.5–12.3 (12.0); dorsal-fin termination to caudal peduncle ventral edge 19.5–20.9 (20.6); anal-fin termination to caudal peduncle dorsal edge 21.4–22.2 (21.8); anal-fin termination to caudal peduncle ventral edge 12.1–13.5 (12.9); first dorsal-fin spine 1.7–2.8 (2.7); second dorsal-fin spine 4.0–5.6 (5.3); third dorsal-fin spine 6.0–7.3 (6.7); first segmented dorsal-fin ray 9.3–11.2 (10.8); fourth last segmented dorsal-fin ray 14.1–17.8 (17.8); first anal-fin spine 1.7–3.2 (2.7); second anal-fin spine 4.7–5.8 (5.6); third anal-fin spine 6.2–7.4 (7.0); first segmented anal-fin ray 9.5–11.4 (10.6); fourth last segmented anal-fin ray 14.3–17.2 (17.2); third pectoral-fin ray 13.6–15.0 (14.7); pelvic-fin spine 8.6–10.2 (10.2); second segmented pelvic-fin ray 21.1–34.1 (34.1); caudal-fin length 19.6–21.5 (21.1).

Live coloration: Females (based on photographs of live individuals in Lembeh Strait and Halmahera and a photograph of a paratype from Batanta Island when freshly dead; Figure 1 ): head and body greyish brown to dark grey, becoming pale grey to pale pinkish grey on lower head and abdomen and yellowish grey on posterior body; scales of dorsal half of head and body, and of anterior part of cheek each with dark grey to black basal spot; posterodorsal part of operculum with two or three large irregular dark grey to black spots, spots decreasing in size ventrally, the largest about as large or larger than pupil; posterior part of cheeks and anterior half of operculum pale blue to pale bluish grey; vertical portion of preopercle dark grey to black; snout, lips and suborbital region dark grey; small dark grey bar in front of each anterior nostril; orbital rim black; bright bluish white to bright blue streak extending along posterior edge of eye to posterior edge of maxilla; iris dark reddish grey, with bright blue suboval ring around pupil; caudal peduncle yellowish grey to bright yellow; dorsal fin greyish to yellowish hyaline, darker grey basally, with one (anteriorly) to about six to eight (posteriorly) grey spots on middle of each interradial membrane, these forming indistinct broken stripes; distal margin of dorsal fin narrowly blue; anal fin greyish to yellowish hyaline, with narrow blue distal margin; caudal fin yellowish grey to grey, darker on dorsal and ventral margins, sometimes with two columns of grey spots on middle of fin; pectoral fins greyish to pinkish hyaline, with dark grey curved bar extending around fin base; pelvic fins pale pink, sometimes with anterior margin narrowly dusky grey. Males (based on photographs of live individuals in Ambon and Lembeh Strait and the holotype from Halmahera, and of a paratype from Batanta Island when freshly dead; Figure 2 ): head and anterior part of body yellowish orange to bright orange, paler ventrally, becoming dark grey posteriorly on body; scales of dorsal half of head and body, and of anterior part of cheek each with dark grey basal spot; posterodorsal corner of operculum with large (about size of pupil) irregular dusky grey to black spot, sometimes with smaller, less-distinct spot immediately below; lower part of operculum and cheek with pinkish or bluish white hue; vertical portion of preopercle dusky grey; small dark grey bar in front of each anterior nostril; bright bluish white streak extending from posterior edge of orbit along posterior edge of maxilla; suborbital area grey to greyish orange; iris bright orange, with bright blue suboval ring around pupil; dorsal fin orangish hyaline anteriorly, becoming greyish hyaline posteriorly, darker grey basally, with one (anteriorly) to about six (posteriorly) grey spots on middle of each interradial membrane, these forming indistinct broken stripes; distal margin of dorsal fin narrowly blue; anal fin greyish hyaline to yellowish hyaline, with narrow blue distal margin; caudal fin greyish to yellowish hyaline, darker on dorsal and ventral margins; pectoral fins pinkish hyaline, with orange curved bar extending around fin base; pelvic fins pale blue to white, edged narrowly with dusky grey to blue.

Preserved coloration: Females: pattern similar to live coloration, head and body becoming dark brown; white markings on head becoming pale brown; dark grey to black markings on head, body and fins becoming dark greybrown; yellow markings on caudal fin becoming pale yellow to pale brown. Males: pattern similar to live coloration, white, yellow, orange and pink markings on head, body and fins becoming pale yellow to pale brown; bluish grey and purple areas becoming dark brown; dark grey to black markings on head, body and fins becoming dark grey-brown.

Habitat and distribution. Known only from north-eastern Indonesia, from North Sulawesi to Papua and extending southwards at least to Ambon ( Figure 3 ). It is a relatively deep-dwelling reef species, having been recorded in depths of 45–66 m in soft bottom habitats below the base of shallower-growing coral reefs. The species is not homogenously distributed over its range, but seems to occur in a very specific microhabitat, which consists of fine silty-sand bottoms with widely-scattered coral rubble and small barrel sponges; the fish invariably take up residence in burrows under the barrel sponges or in large cavities in a coral rubble piece. Another common factor observed at each of the sites from which this species has been recorded is the presence of significant freshwater input from small streams in the nearby vicinity; these streams deposit fine terrigenous sediments that mix with reef carbonate sands to form the silty-sand substrates on which this species is invariably found. Large males and females are generally found in a mated pair, though solitary individuals are also commonly observed, particularly smaller individuals.

Comparisons and relationships. As noted in the introduction, P. erdmanni belongs to a clade characterised by a single synapomorphy: palatine tooth patches inserted medially behind (rather than more or less in line with) vomerine tooth patch. Within that clade, it belongs to phenetic group of species that lack a dark stripe on the body. The five species are very similar in meristic and morphometric characters, but differ in caudal-fin shape and live coloration (see Table 1 ). Two coloration synapomorphies diagnose a clade of four species ( P. erdmanni , P. howsoni , P. m o o re i and P. steenei ) that are allopatrically distributed throughout the Philippines and Indonesia to north-western Australia ( Figure 3 ): dark bar in front of anterior nostril; dark spot on operculum. Relationships within this clade are as follows: Pseudochromis erdmanni + P. moorei + P. steenei (synapomorphy: preopercle with dark edge); P. erdmanni + P. steenei (synapomorphy: pale blue bar behind eye). Pseudochromis erdmanni differs from its sister species ( P. steenei ) in lacking both a broad dark grey to black distal stripe on the anal fin and a similar marking on the anterior part of the pelvic fins.

Remarks. Kuiter and Tonozuka (2001) recognised a single species, P. moorei , from the Philippines to northern Australia, noting (p. 137): “The Bali and Lombok population was recently described as a separate species P. s t e e n e i on the basis of colour differences. The Philippine and northern Australian populations lack white bar behind eye, but in Sulawesi […] it has a short stripe with other body and fin colours identical to Philippine fish.” The implication is that the Sulawesi fish ( P. erdmanni ) are intermediate between P. s t e e n e i, and that there is a single widespread species (with P. howsoni forming the southern form in northern Australia). We interpret the distribution of coloration characters among species in the group as indicating nested sister-group relationships, rather than intermediate forms (see above).

Etymology. Named for Mark Erdmann of Conservation International, Indonesia, who collected the type specimens. Mark has worked closely with the second author for the past six years and is responsible for numerous new discoveries, resulting from his deep scuba collections from the East Indian region, including several new pseudochromids.

Figures

FIGURE 1. Pseudochromis erdmanni new species, female individual, ca. 60 mm SL, Pulau Taunalu, Loloda Selatan, Halmahera, North Maluku Province, Indonesia (photo by G. R. Allen).

FIGURE 2. Pseudochromis erdmanni new species, male holotype, NCIP 6344, 81.5 mm SL, Pulau Taunalu, Loloda Selatan, Halmahera, North Maluku Province, Indonesia (photo by G. R. Allen).

FIGURE 3. Distribution records for Pseudochromis erdmanni (filled circles), P. howsoni (squares), P. m o o re i (triangles) and P. steenei (stars).