Parioglossus galzini

description

Description [holotype values in brackets]. Dorsal fin VI + I, 17 – 18 (three with 17, two with 18) [VI + I, 18]; anal fin I, 17 – 18 (two with 17, three with 18) [I, 18]; pectoral fin 19 – 21 (two with 19, two with 20) [20 on left and 21 on right side]; pelvic fin I, 4; dorsal + ventral procurrent rays 7 – 9 + 8 – 9 (two with 7 + 7, two with 8 + 7) [9 + 8], branched caudal rays 7 + 6; longitudinal scale count 100 – 112 (no count taken from the smallest specimen) [112]; vertebrae 10 + 16; branchiostegals 5. Head and body compressed; body elongate; preopercle naked; scales nonimbricate, scales present on pectoral­fin base, on belly, and from opercular margin to base of caudal fin; mouth terminal, highly protractile, inclined at angle of 70 – 80 º to longitudinal axis of body; maxilla reaching posteriorly to a point below anterior edge of eye; snout short, blunt, less than eye diameter; teeth: outer rows of caniniform teeth and 1 – 2 inner rows of small, slender caniniform teeth; anterior and posterior nostrils a simple pore; 5 head pores present including: posterior nasal pore, anterior interorbital pore, posterior interorbital pore, supraocular pore, infraorbital pore; preopercular

Parioglossus galzini, a new species of ptereleotrid dartfish from Rapa Island (Teleostei: Gobioidei: Ptereleotridae)

diagnosis

Diagnosis. A species of Parioglossus as diagnosed by Rennis & Hoese (1985) distinguished from all described species of Parioglossus by the following combination of characters: dark lateral body stripe absent, preopercular pores absent, 100 or more scales in longitudinal series from above pectoral­fin base to base of caudal fin, pectoral­fin rays 19 – 21, segmented caudal­fin rays 7 + 6, scales nonimbricate, black caudal spot usually sub­triangular (one specimen with spot roughly rectangular), membrane of first dorsal fin attached to second dorsal fin in males and female, mature males with dorsal­fin spines 3 – 5 filamentous and about equal in length, fresh males with narrow yellow stripe running dorsolaterally along body from head to caudal fin.

Parioglossus galzini, a new species of ptereleotrid dartfish from Rapa Island (Teleostei: Gobioidei: Ptereleotridae)

discussion

Comments. Parioglossus galzini differs from P. aporos, P. dotui, P. f o r m o s u s, P. l i n ­ eatus, P. marginalis, P. raoi, P. taeniatus, P. verticalis, P. interruptus, P. sinensis and P. neocaledonicus in lacking a dark lateral stripe in males. The P. sp. of Suzuki et al. (1994) from Iriomote Island, Japan, also has a dark lateral stripe along each side of the body of males. Five Parioglossus species lack a dark lateral stripe in males (P. nudus, P. palustris, P. philippinus, P. rainfordi, and P. triquetrus). Parioglossus triquetrus and P. galzini may be distinguished from these by having a moderate gill opening (open to isthmus), versus narrow (open to side of head near pectoral­fin base). The Rapan Parioglossus galzini and the Fijian P. triquetrus appear to be sibling species. They are similar in appearance in preservative, but differ in several meristic and morphological characters. Both species key out to P. triquetrus in the identification keys published by Rennis & Hoese (1985) and Suzuki & Senou (1994). Parioglossus galzini is easily distinguished from P. triquetrus by having nonimbricate scales (vs. imbricate), longitudinal scale count of 100 – 112 (vs. 83 – 95), the tw

Parioglossus galzini, a new species of ptereleotrid dartfish from Rapa Island (Teleostei: Gobioidei: Ptereleotridae)

distribution

Distribution. The only known specimens were collected from mud and rubble substrates with some scattered sargassum in shallow water (<1.5 m) near the head of Haurei Bay (Fig. 6), Rapa Island (French Polynesia).

Parioglossus galzini, a new species of ptereleotrid dartfish from Rapa Island (Teleostei: Gobioidei: Ptereleotridae)