Foa longimana Weber, 1909

Fraser, Thomas H., 2014, Foa yamba, a new species of cardinalfish (Percomorpha: Apogonidae: Apogonichthyini) from the tidal region of the Clarence River, Australia and redescriptions of the West Pacific Foa longimana and Foa hyalina, Zootaxa 3878 (2), pp. 167-178 : 170-172

Foa longimana Weber, 1909

Figure 3 .

Type material. Holotype ZMA 112.203, 14.2 mm SL, 19 mm TL, Indonesia, Nusa Laut Is., Nahalia Bay, Siboga Sta. 238, pelagic.

Description. For general body shape see Fig. 2 . Proportions as a percent of standard length: body depth 33.1; head length 38.7; eye diameter 10.6; snout length 6.3; bony interorbital width 7.0; upper jaw length 19.0; dorsal-fin spines broken; anal fin spines broken; caudal peduncle depth 18.3; caudal peduncle length 17.6; pectoral-fin rays broken; pelvic-fin rays broken.

Dorsal fins VII‒I,9; anal fin II,8; pectoral-fin rays 14.

Pored lateral line scales 9; transverse scale rows above lateral line 2; transverse scale rows below lateral line ~6; median predorsal scales 4; circumpeduncular scale rows 12 as 5+2+5. Scales on body ctenoid; scales on cheek and opercle cycloid.

Upper arch with 2 rudiments and 1 raker, lower arch with 6 rakers and 3 rudiments as 2+1‒6+3, 7 rakers, 11 total.

Villiform band of teeth on premaxilla and dentary; 1 row of fine teeth on vomer; 3‒4 fine teeth on palatine; none on other bones.

Preserved color pattern. In 70% ethanol, no color patterns remain on head, body or fins. Scattered melanophores are present on the head and body of the holotype ( Fig. 2 A). In German from Weber (1909): “Die Farbe des Alcohol-Exempares is gelblich, überall mit feinen braunen Tüpfeln un Spritzchen. Earte Dorsal, Pektorale und grösster Teil der Ventrale dunkelbraun; die Basis, namentlich nach hinten zu, der 2. Dorsale und der Anale. Caudale hyalin.” Weber & de Beaufort (1929) translation of the original German description: “Colour of alcohol specimen yellowish, mottled all over with fine brown spots. First dorsal, hindermost part of second dorsal and anal, pectorals and greater part of ventral fins dark brown. Caudal hyaline.”

Status of Foa longimana Weber, 1909 . There are only three literature records of Foa longimana: Weber in 1909, Weber in 1913 and lastly Weber & de Beaufort 1929, where the original German description was translated into English. Eschmeyer (2014) has no new entries under Foa longimana or under any other cardinalfish genus. There are no listings in the available online collections. What could be the reasons for the lack of material?

Weber (1909) described Foa longimana from one specimen, 14.2 mm SL (19 mm TL) taken in the water column (pelagic sample), (station 234 in the Siboga text, 238 in the table, p.621) at Nalahia, Nusa Laut, Indonesia. He figured this specimen (here as Fig. 2 B) in the results of the Siboga Expedition (1913, figure 58; also in Weber & de Beaufort). This is a young specimen, perhaps about to settle out of the plankton. Both Foa and Fowleria Jordan & Evermann 1903 have larva with long pectoral fins and the fish flap like butterflies in the water column according to J. Leis (personal communication). The type has a slender body depth at 33% of standard length taken from the specimen by me in 1972. Most species of Foa have body depths of 37% or greater in standard length ( Fraser & Randall, 2011; this paper) The pectoral fins are damaged but figure 58 suggests the length is about 30% of standard length where as the head length is 38.7% of standard length. Weber described the pectoral fin as “Pektorale fast so lang wie die Körperhöher.” “...almost as long as the head”. Most species of Foa have pectoral fin lengths of 21–26% of standard length ( Fraser & Randall, 2011; this paper). Only the number of pored lateral line scales at 11 reported by Weber (my count was nine) and the presence of palatine teeth (3‒4 teeth) are in favor of Foa . There is known variation in the number of pored lateral line scales with size for Foa ( Fraser & Randall, 2011) . This holotype cannot be certainly identified.

Alternative I. It is a species of Foa . The reason for the differences in body depth is allometric growth after settling out of the plankton. I have no data to accept or reject this growth assertion (a likely change) and likely no way to identify the adult form because of poor color pattern information. Pectoral fin-ray counts for species of Foa are usually 12 not 14.

Alternative II. It is a species of Neamia Smith & Radcliffe in Radcliffe 1912. Adult Neamia have 22–24 pored lateral line scales, where as small specimens 17–20 mm SL have been reported with pored lateral line scales of 11–12 ( Fraser & Allen, 2006). Known characteristics fit with Neamia articycla except for the typical ocellus present on the opercle of N. articycla Fraser & Allen 2006 . Weber’s species agrees in the proportions for body depth and pectoral-fin length, pectoral-fin ray count of 14 and cycloid scales on the cheek, VII first dorsal spines, pored lateral line scales, palatine teeth and number of pectoral fin-rays.

Alternative III. It is a species of Apogonichthys Bleeker 1854 . Palatine teeth are absent in species of this genus. Assume that small Foa longimana lose these four teeth with age/size. If so, some known characteristics fit with Apogonichthys perdix Bleeker 1854 , A. landoni Herre 1934 or A. ocellatus ( Weber 1913) . The best fit as an Apogonichthys is with A. perdix , because A. ocellatus has a high pectoral fin-ray count of 17–18 and an ocellus in the first dorsal fin. Apogonichthys perdix has a deeper body depth so allometric growth would have to occur. Both Apogonichtys perdix and A. landoni agree in the cycloid scales on the cheek, VII first dorsal spines, and number of pectoral fin-rays.

Alternative IV. It is a species of Fowleria . Palatine teeth are absent in species of this genus. Assume that small Foa longimana lose these teeth with age/size. The best fit with species of Fowleria is with F. vaiulae Jordan & Seale 1906 because it lacks an ocellus on the opercle. Some allometric growth would have to occur. It agrees in cycloid scales on the cheek and VII first dorsal spines.

Weber’s type specimen exists (ZMA112.203), and his description meets the requirements of the International Code of Zoological Nomenclature to be a valid name. No additional specimens have been reported in the literature. Its true identity is a mystery. At present, it cannot meet the Code’s date requirement under Article 23.9 relating to the lack of use applied to an older name after 1899 as a nomen oblitum, that is, reversal of priority. A reasonable junior synonym cannot be identified, although the genus Neamia has the best morphological fit. The name is treated here as a nomen dubium in the Apogonichthyini Snodgrass & Heller 1905 in Mabuchi et al. 2014. Weber’s name remains available should better information emerge, such as raising specimens among the four alternatives from eggs or larvae that lead to a species identification.

Figures

FIGURE 2. Foa hyalina. A. Live, Madang, Papua New Guinea, by G. R. Allen. B. Positive radiograph of paratype of Apogon hyalina, USNM 171126, 33.7 mm SL, by S. Raredon. C. Enlarged section of the caudal skeleton showing five hypurals.

FIGURE 3. The holotype of Foa longimana, 14.2 mm SL, 19 mm TL, ZMA 112.203. A. Holotype, preserved in ethanol, photograph by Z. Randall. B. Figure scanned from Weber’s Die Fische der Siboga-expedition (1913: 258, Figure 58, by M. Weber). The same figure is on p. 354, figure 83 of Weber & de Beaufort (1929).