Litobranchus fowleri (Herre 1936)

Litobranchus fowleri (Herre)

Salarias fowleri Herre, 1936, p. 364, pl. 2, fig. 7 [original description; type-locality: Philippine Islands, Oriental Negros, tide pool at Dumaquete].

MATERIAL EXAMINED.—SU 30971 (adult female, 29.9 mm SL), holotype of Salarias fowleri and paratypes (6 [2 not seen], 16.0–28.2) in same bottle, Philippine Islands, Oriental Negros, tide pool at Dumaquete, lat. 9°18′N, long. 123°18′E, 23 April 1936, A. W. C. T. Herre; USNM 203763 (1, cleared and stained, 27.4), paratype originally with SU 30971; data for following collections same as SU 30971, except for date of collection: SU 29582 (11 [3 not seen], 23.7–34.4), SU 32295 (1, 28.8), SU 40244 (1, 26.4), SU 40246 (1, 28.1), USNM 203768 (1, 30.9), and USNM 203769 (2, including 1 cleared and stained, 31.0–32.0). ZMA 109.098 (1, 31.0), original no. Siboga Expedition sta. 33, Indonesia, Lombok, Pijut Bay, lat. 8°47′S, long. 116°31′E, depth 9–22 meters, 24/26 March 1899, M. Weber; ZMA 109.097 (1, 24.8) and 109.099 (2, 25.1–30.2), New Guinea, Waigeo Island, Saonek Anchorage, lat. 0°21′S, long. 130°56′E, December 1909, L. F. de Beaufort; CAS 24687 (3, 18.7–23.6), GVF Reg. #881, sta. 95, Palau Islands, tide pool on reef off SW point of Nardueis Island, lat. 7°20′44"N, long. 134°35′08"E, 4 September 1956, H. A. Fehlmann and A. W. Scott; CAS 24688 (1, 22.0), GVF Reg. #901, sta. 115, Palau Islands, Peleliu, south side of channel between Ngurungor Point and Ngusuwal Island, east side of Peleliu, lat. 7°00′36"N, long. 134°16′26"E, depth 0–0.5m, tide pool, rock, and sand bottom, 19 September 1956, H. A. Fehlmann, et al.; CAS 24689 (2, 23.9–34.5), GVF Reg. #1600, sta. 20, Philippine Islands, tide pools at Ayuguiton, 14 km south of Dumaquete City, Oriental Negros, 19 April 1958, W. C. Brown, et al.

DESCRIPTION.—(Meristic characters for holotype in parentheses). Dentary a closed capsule with replacement teeth entering functional series through foramina in jawbone. Posterior dentary canines present (frequently absent in females). Premaxillary and dentary teeth immovable or nearly so; premaxillary teeth 36 to 42; dentary teeth 28 to 30. Vomerine teeth absent. Terminal vertebra with two epurals and autogenous hypural 5 and ventral hypural plate. Vertebrae 10 + 27 or 28 (usually 28) = 37 or 38; epipleural ribs 13 or 14; last pleural rib on vertebra 10. Circumorbital bones 5.

Dorsal spines 12; last spine moderately reduced; segmented rays 18 to 20(19); basal two-thirds of terminal dorsal ray bound by membrane to caudal peduncle; dorsal fin moderately incised between spinous and rayed portions. Anal spines 2; segmented rays 20 to 22(21); basal two-thirds of terminal anal ray bound by membrane to caudal peduncle. Caudal fin with 12 segmented rays, none branched; dorsal procurrent rays 5 to 8 (usually 6), ventral rays 4 or 5. Pelvic rays I,3. Pectoral rays 14. Pectoral radial formula 2–0–2. Gill-rakers 6 to 8(7). Pseudobranchial filaments 5. Nuchal, supraorbital, and nasal cirri simple. Upper and lower lips entire. Pores of infraorbital series simple. Lateral line short, continuous to point below 4th to 6th dorsal spine, pores simple.

PIGMENTATION.—The pigmentation of the sexes closely approaches that shown in Figure 12. Males are characterized by 7 dark lateral bands that extend across the dorsum, several rows of pale, horizontally elongated spots on sides, and the fins not heavily pigmented, except distally on the interradial membranes of the anterior 4 or 5 dorsal spines. In several of the largest (presumably nuptial) males the head is very dark. In the females there are no rows of pale spots and the lateral bands are less well defined. In contrast to the males, the body and the dorsal fin are characterized by numerous dark spots.

GEOGRAPHIC VARIATION.—The three New Guinea specimens differ in several respects from the other material and were not used in preparing the above description. We provisionally assign these specimens to Litobranchus fowleri.

In specimens from the Palaus, Philippines, and Indonesia, the supraorbital cirri are minute and there is no apparent sexual dimorphism associated with these structures. In 7 females (21.8–31.0 mm SL) the ratio of the cirrus length into the orbital diameter was 4.3 to 8.5, average 5.6; in 10 males (22.4–34.0) the ratio was 4.0 to 8.0, average 5.4. The New Guinean specimens have longer cirri that clearly reflect sexual dimorphism. In the single female specimen the cirri/orbital ratio is 1.8; in both males it is 0.65. In all three specimens the number of dentary teeth is low, 23 (versus 28 to 30). The number of premaxillary teeth is within the range of those shown by the other specimens.

The interradial membranes of the anal fin are more deeply incised and the anal segmented rays approximately one-third longer in New Guinean males than in Philippine males of nearly equal size. The New Guinean males also differ in having the body almost completely devoid of pigment, but this may be the result of fading.