Threatened fishes of the world: Papillogobius punctatus Gill & Miller, 1990 (Gobiidae)

Abstract

Common name: None. Conservation status: Nominated for vulnerable status in the Australian Society for Fish Biology’s list of Australian threatened fishes. Identification: Dl IV-VI, D2 I,7-I,9, A 1.8-1.9, P 15-16, V 15, C 16-17, scales in lateral series 27-31, scales in transverse series 7-8, predorsal scales O-5, gill rakers (l-2) + (8-9), vertebrae 26, relationship between pterygiophores and vertebrae 3/II II I I O/9. Maximum size, female 44.8 mm SL (52.8 mm TL), male 52.9 mm SL (67.1 mm TL). A small estuarine goby with a moderately elongate body which is deepest at the middle of the first dorsal fin. Postorbital profile shallow, snout oblique and shorter than the eye diameter. Second ray of the first dorsal fin free at the tip, often extending to the caudal peduncle. Trunk bearing five large blotches and five to seven longitudinal rows of yellow to red-brown spots. Dorsal, caudal and pectoral fins bearing yellow to red-brown spots proximally. Branchiostegal membrane heavily pigmented. Drawing by Howard Gill. Distribution: Despite extensive sampling in coastal embayments, estuaries, rivers and lakes P punctatus has only ever been captured from a very small section in the upper and middle estuary of the Swan River, Western Australia (Gill & Miller 1990; Gill & Potter 1993). Abundance: Within its very restricted range P punctatus is reasonably abundant. Habitat and ecology: P punctatus is typically found on the shallow sand flats (< 2 m) of the lower section of the upper Swan estuary. Females and juveniles are more abundant in the shallower water whereas males are more abundant on the dropoff into deeper water (Gill&Miller 1990; Gill & Potter 1993). Water temperature ranges from 10-32” C and salinity from just above 0 to 34%,. Polychaetes and amphipods were the main prey items ingested in all seasons (unpublished data). Reproduction: The presence of larvae and juveniles of II punctatus from mid-spring to late autumn with a peak in abundance in mid to late summer (January and February) suggest that this species has a protracted spawning period that peaks in late spring to early summer (Neira et al. 1992). Due to the very small number of P punctatus caught, the age at first breeding has not been established. Threats: The main threats to this species are the loss of habitat that may occur due to bridge building and land reclamation for urban developments, and also the deposition onto the sand flats of silt and pollutants associated with dredging and urban run-off. N.B. A closely related species (Favonigobius lateralis) has been shown to be intolerant of a substrate that contains fine particles (Gill & Potter 1993). Conservation actions: This species has been nominated for inclusion on the list of Australian threatened fishes compiled by the Australian Society for Fish Biology. Conservation recommendations: The most important conservation actions are the preservation of the sand flats of the lower section of the upper Swan estuary and the monitoring of urban development in this area of the estuary. While the taxonomy of this species has received much recent attention (Gill & Miller 1990; Gill et al. 1992) little is known about its general biology, a situation which must be addressed before further recommendations can be made. Remarks: I? punctatus is the sole representative of this Indo-Pacific genus in south-western Australia and appears to be restricted to a small region of the Swan River, where in the past it was often confused with the superficially similar E

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