Pseudoambassis macleayi Castelnau, 1878

Gill, Anthony C., Russell, Barry C. & Nelson, Gary, 2018, F. L. de Castelnau’s Norman River fishes housed in the Macleay Museum, University of Sydney, Zootaxa 4459 (3), pp. 565-574 : 567-568

Pseudoambassis macleayi Castelnau [= Ambassis macleayi ]

Figure 2

Pseudoambassis macleayi Castelnau 1878b: 43 (type locality, Norman River). Castelnau (1878b: 43) described Pseudoambassis macleayi from “numerous specimens, the largest being under two inches and a half long” from the Norman River. Macleay (1881) simply listed the species in his catalogue of Australian fishes. McCulloch (1929b) considered it as a valid species of Ambassis , but did not indicate whether he had seen any type specimens. Whitley (1935: 358) noted: “There are three specimens of macleayi in the Macleay Museum for the Norman River, and the largest, 52 mm. in standard length, is selected as the lectotype of the species.” He mistakenly believed that Pseudoambassis Castelnau (1878b) was preoccupied by Pseudambassis Bleeker (1874) , and erected a replacement name, Austrochanda , for P. macleayi . Allen & Burgess (1990) considered P. macleayi as a valid species of Ambassis , and noted (p. 171): “Whitley (1935) designated a specimen, 52 mm SL, from the Norman River as lectotype. It was part of the Macleay Museum collection that was eventually transferred to the Australian Museum. However, this specimen is apparently lost, as it could not be located during the present study.”

Eschmeyer et al. (2018) noted that the lectotype of P. macleayi is in MAMU, but also listed a specimen in the Queensland Museum (QM I.5332) as a paralectotype, and further remarked that two specimens had been exchanged to the AMS from the QM. However, J. Johnson (pers. comm.) confirmed there are eight specimens of an original 10 in QM I.5332; the two missing specimens were exchanged to the AMS (AMS IA.6057–58). The hand-written label for the jar says “ Pseudoambassis convexus De Vis Queensland cotypes”. The original registry entry for the jar says “ Austrochanda macleayi ” in the identification column, and in the remarks column says “ paratype of Pseudoambassis convexus, De Vis ” followed by “ 2 specimens exchanged to Aust. Mus. April 10, 1934 ”. These details are consistent with Whitley’s (1935) treatment of Pseudoambassis convexus De Vis (1884) , which he considered to be a synonym of Austroambassis macleayi , noting (p. 358) “ Types in Australian and Queensland Museums examined.” The identification of the QM specimens transferred to the AMS as A. macleayi is thus attributable to Whitley. Whether the remaining specimens in the QM are truly types of P. convexus is less certain (J. Johnson, pers. comm.).

There are three specimens in the Macleay Museum collection (MAMU F.433), which measure 36.0, 40.4 and 50.2 mm SL (TL not determinable for any of the specimens owing to severe damage of the caudal fins). The old external label for the jar says “ PSEUDOAMBASSIS MACLEAYI, Casteln. NORMAN RIVER ”; an internal card similarly says “ Pseudoambassis Macleayi, Casteln. Norman River, N. Australia ”. The specimens match an index card, which states: “ Pseudoambassis macleayi, Cast. […] 2 sp. 1½″–2½″ Norman River”. The miscount of two rather than three specimens is probably a result of the counting having been made with the specimens still in the jar, with one being overlooked. There are similar miscounts for other MAMU index cards. Jenny Anderson’s entry in the catalogue of the Macleay Museum fish collection lists three specimens, which she mistakenly listed as mere ‘topotypes’. They were therefore not listed in Stanbury’s (1969) type catalogue, and accordingly were excluded from the 1970 transfer of fish types to AMS.

The specimens in MAMU F.433 are fragile and appear to have been desiccated at some stage. Nonetheless, it was possible to ascertain the following characters, which in combination are diagnostic for Allen & Burgess’s (1990) concept of Ambassis macleayi : single supraorbital spine; no nasal spine; two transverse scale rows on cheek; 10 segmented rays each in dorsal and anal fins; lateral line incomplete; pectoral fin with 15 rays (checked in lectotype only). We therefore regard the three specimens in MAMU F.433 as the lectotype and paralectotypes of A. macleayi .

Figures

FIGURE 2. Pseudoambassis macleayi Castlenau, lectotype, MAMU F. F.433, 50.2 mm SL. Photo by Y.K. Tea.