Neosillago Castelnau, 1875

Ho, Hsuan-Ching, 2013, Redescription of Parapercis punctata (Cuvier, 1829) and status of Neosillago Castelnau, 1875 and its type species Neosillago marmorata Castelnau, 1875 (Perciformes: Pinguipedidae), Zootaxa 3736 (3), pp. 291-299 : 296-298

Status of Neosillago Castelnau, 1875 and N. marmorata Castelnau, 1875

The holotype of Neosillago marmorata Castelnau, 1875 was found in the fish collection of Muséum national d'Histoire naturelle, Paris (MNHN A-3524, Fig. 3 ), together with many other specimens sent from Australia by Count F. de Castelnau who was Consul-General for France in Melbourne from 1863–1877. Castelnau was a prolific ichthyologist who published 10 papers on Australian fishes and described some 275 new species from Australia, including N. marmorata (Russell et al., 2010; B. Russell, pers. comm., 2013).

The holotype specimen is partly damaged and is in poor condition. Selected data are provided in Table 2 . Castelnau (1875) gave the size of the fish as “ little more than 5 inches ” which agrees with the size measured (126.5 mm [= 5 inches] total length, with the caudal fin partly broken). The locality (Port Walcott, Western Australia) is also confirmed on the label.

Castelnau (1875:16) defined Neosillago as: “ cleft of the mouth horizontal, with the lower jaw rather prominent; two dorsals, the first with five spines; ventrals rather in advance of the pectorals; palatine teeth; canines very long; preopercule entire; opercula with two strong spines; pectorals formed of simple rays; body elongate, covered with moderately small scales; snout elongate.” He suggested that it is close to Sillago . However, all sillaginids have the pelvic-fin origin below or slightly behind the origin of pectoral fin, lower jaw slightly inferior and lacking enlarged canines (Kaga, 2013; pers. obs.). The other characters provided by Castelnau (1875) are non-diagnostic and can be assigned to many fish genera, except for some doubtful characters (see below).

By combining both the definition of the genus and the description of the species provided by Castelnau (1875), the following characters place it in Parapercis : (1) 5 spines on first dorsal fin; (2) 21 rays on second dorsal fin (3) an external series of canines on upper jaw with the front teeth large and arched; (4) 6 very large arched canines in front, 3 on each side, of lower jaw; (5) teeth present on the vomer and palatines (but apparently a mistake, see below); (6) cheeks scaly; (7) second dorsal fin inserted near the first dorsal fin; and (8) ventral fin in front of the pectoral fin, below the spines of the operculae.

The following characters provided by Castelnau (1875) more specifically indicate the similarity of Neosillago marmorata to Parapercis nebulosa (Quoy & Gaimard, 1825) : (1) caudal fin bilobed; (2) 75 scales on the lateral line (assuming he included those on the caudal-fin base); (3) 6 large obscure rounded blotches extending on each side of the lateral line; (4) spinous dorsal-fin membrane black; (5) teeth present on the vomer and palatines; (6) 6 canines in front of lower jaw; (7) 5 dorsal-fin spines and the fourth spine longest; and (8) all other fins are immaculate and white (in preservation).

On the other hand, some characters provided by Castelnau (1875) are problematic. He mentioned that the holotype has 2 spines on the opercle, but this is not strictly consistent with Parapercis . The holotype has one additional, smaller spine above the larger principal spine, but it is entirely covered by skin. This condition has also been observed in other congeners (pers. obs.). It is also very possible that Castelnau meant one opercular spine plus one subopercular spine, because the holotype has a strong blunt spine on the subopercle.

Castelnau (1875) also described his specimen as having 12 pectoral-fin rays (all simple), 21 dorsal-fin rays and 17 anal-fin rays. I counted 17 pectoral-fin rays (all but the uppermost ray branched), 21 rays in the dorsal fin and 1 spine plus 17 rays in the anal fin for the holotype. The status of simple rays in the pectoral fin is apparently a mistake, because all perch-like fishes (or fishes with similar appearance) usually possess branched rays, except for the uppermost 1 and/or the lowermost 1 or 2 rays (pers. obs.; G.D. Johnson, pers. comm., 2013). It is notable that the 21 dorsal-fin rays and 17 anal-fin rays are rare in P. nebulosa , but it still falls within the range of the species (see Cantwell, 1964: tables 2–3).

Castelnau (1875) stated that teeth were present on both vomer and palatine bones. However, species of Parapercis with teeth on the palatines have 23 or more dorsal-fin rays (rarely 22) and 20 or more total anal-fin elements (Cantwell, 1964; Randall, 1999), except for those species in Parapercis cylindrica complex (sensu Randall, 2003), which have a more short and compressed body, more pointed snout, 4–6 predorsal scales and a low lateral-line scale count (38–59 pored scales, not including those on caudal fin base). Thus, the presence of teeth on the palatine was apparently a mistake. Based on my examination, the holotype does not have teeth on palatines.

Castelnau (1875) also described “ the head and the anterior half of the body are red and the posterior half of the latter white ”. However, no pinguipedids has this coloration (i.e., different major coloration on anterior and posterior body), and I infer he meant that the head and the dorsal half of the body are red and ventral half of body white, which would be consistent for this group.

The caudal fin of the holotype of N. marmorata is broken and the shape of the fin cannot be determined. According to Castelnau (1875) N. marmorata possesses a bilobed caudal fin, which is not common in Parapercis , except for Parapercis natator Randall, Senou & Yoshino, 2008 , Parapercis schauinslandii Steindachner, 1900 and P. nebulosa . Other congeners have either only one prolongation on the upper caudal lobe, or lack prolongation on both lobes of the caudal fin. The holotype of N. marmorata can be easily distinguished from P. natator and P. schauinslandii by having 69 or 70 pored lateral-line scales (not including smaller scales on caudal fin base, vs. 59– 61 in P. natator and 56–58 in P. schauinslandii , data from Randall et al., 2008).

Other information based on examination of the holotype of N. marmorata is: row of 5 conical teeth on vomer; anterior 8 teeth on outer row of upper jaw large and curved, first 2 distinctly largest; head pores not available; scales on cheek, nape, opercle and caudal fin lost; scales on chest weakly ctenoid, on space in front of pectoral-fin base ctenoid, on pectoral-fin base ctenoid, and on abdomen ctenoid.

In summary, morphology, morphometrics and meristics show that the holotype of N. marmorata closely matches P. n e b u l o s a based on both the description provided by Castelnau (1875) and examination of the holotype. Hence, Neosillago Castelnau 1875 is proposed here as a junior synonym of Parapercis Bleeker, 1863 , and N. marmoratus Castelnau 1875 is proposed as a junior synonym of P. nebulosa (Quoy & Gaimard 1825) . Detailed morphometrics and meristic data of the holotype compared to those of P. nebulosa are provided in Table 2 .

Figures

FIGURE 3. Holotype of Neosillago marmorata Castelnau, 1875 (= Parapercis nebulosa), MNHN A- 3524, 111.3 mm SL, preserved.

Tables

TABLE 2. Morphometric and meristic data of holotype of Neosillago marmorata and non-type specimens of Parapercis nebulosa.

	N. marmorata	P. nebulosa
	MNHN A-3524	MNHN A-3104, MNHN 1981-57
SL (mm)	111.3	127.3–186.1 (n = 5)
% SL
Head length	26.4	27.0 (25.2–28.5)
Body depth	13.5	17.9 (16.9–18.9)
Body width	14.4	18.1 (17.2–18.5)
Snout length	7.6	9.3 (8.9–9.7)
Orbital diameter	7.2	6.1 (5.2–6.7)
Interorbital width	–	5.0 (4.6–6.1)
Upper-jaw length	9.7	10.4 (9.5–11.9)
Pre-dorsal length	27.6	27.9 (27.0–28.5)
Pre-pelvic length	23.2	23.9 (21.6–25.9)
Pre-anal length	45.6	45.5 (43.9–48.3)
Dorsal-fin base	63.9	64.3 (60.7–66.6)
1st dorsal-fin spine	4.7	4.2 (3.5–5.3)
2nd dorsal-fin spine	6.8	5.2 (4.4–6.3)
3rd dorsal-fin spine	7.3	6.6 (5.7–8.1)
4th dorsal-fin spine	6.5	5.9 (4.8–7.5)
5th dorsal-fin spine	4.9	4.3 (3.6–4.9)
Longest dorsal-fin ray	–	11.7 (10.9–12.6)
Anal-fin base	44.7	46.2 (44.0–46.4)
Anal-fin spine	5.3	4.0 (2.9–5.1)
Longest anal-fin ray	–	10.3 (9.5–11.3)
Pectoral-fin length	–	19.9 (19.2–20.8)
Pelvic-fin length	20.2	20.5 (19.7–22.8)
Pelvic-fin spine	8.5	4.6 (2.9–7.6)
Caudal-fin length 1	–	14.7 (13.2–16.4)
Caudal-fin length 2	–	21.9 (19.1–27.6)
Caudal-fin length 3	–	20.7 (18.9–24.0)
Meristics
Dorsal-fin rays	V, 21	V, 22
Anal-fin rays	I, 17	I, 18
Pectoral-fin rays	17/17	16 or 17
Pored lateral-line scales	ca. 69/70	69–76
Pre-dorsal scales	ca. 13	12 or 13
Scale rows above lateral-line	ca. 9.5	9.5–11.5
Scale rows below lateral-line	ca. 24	24–26
Circumpeduncular scales rows	36	34–38
Pseudobranchial filaments	ca. 23	23
Gill rakers	6 + 11 = 17	6–7 + 9–12 = 15–19