FIRST REPORT OF TEARDROP THREADFIN BREAM, NEMIPTERUS ISACANTHUS (ACTINOPTERY GII: PERCIFORMES: NEMIPTERIDAE), FROM THE SOLOMON SEA, PAPUA NEW GUINEA

. The teardrop threadﬁ n bream, Nemipterus isacanthus (Bleeker, 1873), is reported from northern New Guinea for the ﬁ rst time based on specimens caught by hook and line

The senior author observed Nemipterus isacanthus in Papua New Guinea when photographing a June 2008 catch by the junior author, who resides at KWMA. An image including several individuals was used by Longenecker et al. (2008) to represent a typical subsistence catch at KWMA, and later appeared on the cover of a fi shery-monitoring curriculum (Longenecker et al. 2012). The senior author encountered the species again at KWMA on 11 September 2014 when photographing another catch by the junior author.
Several lines of evidence suggest that a large and permanent population of Nemipterus isacanthus exists at KWMA. First, the species is common enough to have a local name. It is called imili in Kala (the vernacular language at KWMA and fi ve nearby villages). Second, KWMA residents can describe the habitat where N. isacanthus is most likely to be caught (over sand near the edge of coral reefs, at depths between 30 and 90 m). Third, fi shermen at KMWA suggested it would make a good candidate for rapid reproductive analysis (see Longenecker et al. 2014) because they could easily catch the required 125 specimens within the four-month period allotted for collection. In fact, they caught 98 specimens during 12 days of fi shing in February 2015. Fourth, it appears to form a large part of the subsistence fi sh catch at KWMA. N. isacanthus represents 23% of individuals in the senior author's photographs of the junior author's two catches.
The presence of Nemipterus isacanthus at KWMA represents an approximately 1400 km range extension for the species (Fig. 1). Russell (1990) listed its distribution as the Philippines, Gulf of Thailand, Strait of Malacca, Indonesia, and northern Australia. The distribution map in Russell (1990) indicates that, north of New Guinea, the eastern limit is located between Mindanao (Philippines) and the northeastern tip of Sulawesi (Indonesia), whereas south of New Guinea, the eastern limit is the Gove Peninsula, northern Australia. The distance between these limits and KWMA is approximately 2750 and 2300 km, respectively. The latter distance is the shortest water route between Gove Peninsula and KWMA (i.e., around the eastern tip of New Guinea). We also examined georeferenced occurrence records from the Global Biodiversity Information Facility [GBIF.org (23rd February 2016) GBIF Occurrence Download http:// doi.org/10.15468/dl.shlvzh GBIF]. These records indicate that, north of New Guinea, the collection site nearest KWMA was on the west side of Luzon (Philippines), whereas south of New Guinea, the collection site nearest KWMA was in the Gulf of Carpentaria The distance between these points and KWMA is approximately 3750 and 1900 km, respectively. Again, the latter distance represents the shortest water route. Finally, the shortest water route between KWMA and the site where it was reported by Alongi et al. (1992) in the Gulf of Papua is approximately 1400 km.
Habitat suitable for Nemipterus isacanthus almost certainly exists between KWMA and its previously reported occurrences and distributional limits. The rarity of previous reports from New Guinea may refl ect limited collecting effort. It seems reasonable to include New Guinea in the principal range of N. isacanthus.
No specimens of Nemipterus isacanthus from New Guinea have been deposited in museum collections. Here we use the terminology of Russell 1990 to describe N. isacanthus at KWMA based on meristic counts taken from fresh specimens collected 11 September 2014; and morphological, morphometric, and colour characters obtained by examination of photographs of one of the specimens (Fig. 2). Morphometric measurements were made with image analysis software. Meristic and morphometric data are presented in Table 1. Head: lower margin of eye located above a line drawn from tip of snout to upper base of pectoral fi n; a line drawn from posterior edge of suborbital reaching dorsal profi le 2 scale rows before origin of dorsal fi n. Body: scales below lateral line arranged in near-horizontal rows. Pectoral fi ns reach beyond anus. Dorsal fi n continuous; membrane between spines slightly emarginate; fi rst two spines separated by a membrane, shorter than the following spines, and not produced into a long fi lament. Anal fi n: last ray elongate. Caudal fi n: forked; upper lobe falcate, not produced into an elongate point or extended into a narrow fi lament. Colour: background of head and body pink dorsally, fading to silver-white ventrally; upper lip yellow; yellow bar extending obliquely forward from bottom of eye toward angle of mouth; two pale yellow stripes along body, the superior one from beneath origin of lateral line to upper caudal fi n base, the inferior one from behind pectoral fi n base to lower caudal fi n base; ventral surface yellow from isthmus to caudal fi n base; dorsal fi n translucent, with narrow yellow margin and submedial stripe; caudal fi n pink, tip of upper lobe bright yellow. The maximum and average fork length of 125 specimens collected February-June 2015 was 24.9 and 15.2 cm, respectively. These characters agree completely with Russell (1990), the aidto-identifi cation used to identify the specimens. Nemipterid fi shes of the world (threadfi n breams, whiptail breams, monocle breams, dwarf monocle breams, and coral breams). Family Nemipteridae. An annotated and illustrated catalogue of nemipterid species known to date. FAO Fisheries Synopsis.