Marphysa mossambica (Peters, 1854)

Eunice mossambica Peters, 1854: 612.

Nauphanta novae Hollandiae Kinberg, 1865: 564; 1910: 43, pl. 16, fig. 23, 23B, C, F, G.

Marphysa mossambica. – Gravier, 1900: 267, pl. 14, figs 89−90, text figs. 137−137; Crossland, 1903: 139 −140, pl. 15, figs 7−10; Day 1967, 395, fig. 17.5 i −m.

Marphysa simplex Treadwell, 1922: 151 −152, text-fig. 39, pl. 5, figs 8−12.

Nauphanta mossambica. – Fauchald, 1987: 376 −378, fig. 1.

Material examined. Australia, Northern Territory, Ludmilla Creek mouth, 12˚24.8' S 130˚50.0' E 1(NTM W60), 1(NTM W61), coll. R.J. Hanley, 18 Dec. 1981, inside rotting timber among mangroves; same location 1(NTM W67), coll. R.J. Hanley, 26 Nov 1981, burrowing in mangrove mud; same location, 2(NTM W153), coll. R.J. Hanley, 12 Mar. 1982, in mud among roots of Rhizophora stylosa, Gunn Point, 12˚9.5' S 131˚00.5' E, 2(NTM W154), coll. R.J. Hanley, 4 Oct. 1981, inside rotting timber, R. stylosa, Field Island, 12˚06.90’S 132˚25.20’E, muddy reef, coll. C.J. Glasby, 20 Aug. 2004, 1(NTM W23043). Western Australia, Kimberley region, coll. R.J. Hanley, 1994, RH 94/11, 1(NTM W23044), 5(NTM W23045).

Comparative material. Marphysa mossambica sensu Monro, 1931, Low Isles, Queensland, 16˚23’S 145˚34’E, Great Barrier Reef, Sts A19, 19a, coll. 18.4.1929, 2(AM W2956).

Description. Present material ranged from 2.2–9.0 mm maximum body width. Branchiae first present on chaetiger 14−46, maximum number of filaments (3−6) on mid-posterior body. Pectinate chaetae asymmetrical throughout, with 15–25 teeth in anterior chaetigers, 30−40 teeth in posterior chaetigers; bidentate subacicular hooks from chaetigers 23−68, continue as one per parapodium for several chaetigers then disappear for few chaetigers, but may reappear again later [Crossland (1903) also commented on the loss of chaetae in the mid- and posterior body parapodia, particularly subacicular hooks, in this species; but this feature may be more widespread across the family (Zanol et al. 2007)].

Remarks. The synonymy of Nauphanta novaehollandiae with M. mossambica, first proposed by Gravier (1900) was supported by Crossland (1903) and Augener (1922). However, Fauchald (1987) disagreed, considering that the types of both species differed sufficiently such that the two species could be recognised, viz. ‘branchiae are present from setiger 30 and subacicular hooks from setiger 44 in Nauphanta novaehollandiae; branchiae are present from setiger 37 or later and subacicular hooks not until setiger 58 in N. mossambica ’. Also, he found slight (but unspecified) differences in shape of the subacicular hooks. However as demonstrated below, the differences in where the branchiae and hooks start can be accounted for by size-related variation taking into consideration the much smaller size of the holotype of Nauphanta novaehollandiae compared to the lectotype of N. mossambica (117 chaetigers, 4 mm wide compared to 420 chaetigers, 10 mm wide) (Fig. 4A, B). The range of variation in these two characters in our material (branchiae from chaetigers 14−46, subacicular hooks from chaetigers 23−68) encompasses both species.

The present material shows a positive linear relationship between body size (x) and the chaetiger on which the branchiae and subacicular hooks appear, as follows:

Branchiae, y = 5.2999x – 1.8029 (r2 = 0.94; n = 15; P <0.001)

Subacicular hooks, y = 7.4469x + 5.0369 (r2 = 0.89; n = 15; P <0.001)

When the data for the lectotype of M. mossambica (which at 10 mm wide is about the same size as the larger specimens in this study) and the holotype of M. novaehollandiae were included in the analysis the regression values decreased slightly for both branchiae and subacicular hooks (viz. r2 = 0.86 and r2 = 0.87 respectively), but the change was not statistically significant (P <0.001; Fig. 4A, B). Therefore, it is highly likely that the northern Australian forms, the lectotype of M. mossambica from Mozambique, and the holotype of M. novaehollandiae represent populations of a single species.

The synonymy of Marphysa simplex Treadwell, 1922, described from Suva Harbour, Fiji with Marphysa mossambica is newly proposed. Although Treadwell apparently misreported the chaetiger (=somite) on which the branchiae begin as somite 242 (the total number of somites was reported to be about 200!), all other key features agree with those of a small-sized specimen of Marphysa mossambica. Notwithstanding the relegation of Marphysa simplex Treadwell, 1922 to junior synonymy, this is the second case of secondary homonymy in the genus, the senior homonym being Marphysa simplex Langerhans, 1884 (as Amphiro simplex) from Madeira.

Other records of M. mossambica from Australian waters are confused. The record of the species from Saint Vincent Gulf South Australia by Fauvel (1917) is a misidentification as he illustrates the presence of a compound spiniger, which places it in the B2 Marphysa group. The second report of the species from Australia—from the Low Isles, Great Barrier Reef by Monro (1931) —could not be verified as the two specimens now lack anterior chaetigers including the head. The only other records of the species from Australia are Kinberg’s original description of N. novaehollandiae from Sydney Harbour (holotype later redescribed by Fauchald 1987), and Augener’s (1922) report of Marphysa novaehollandiae from Cape York, Queensland.

Distribution. Tropical and subtropical Indo-west Pacific including Zanzibar, Mozambique, Red Sea, northern Australia, Philippines and Fiji.

M. fauchaldi M. borradailei M. furcellata M. graveleyi M. macintoshi M. M. mullawa M. M. teretiuscula M. tamurai

n. sp. mossambica orientalis (= M. simplex)

Mandibles lighter black and lighter lighter black, no dark brown, brown, white dark brown, white edging dark brown,

coloured white coloured coloured white edging lighter cutting plate white present whitish

cutting plate cutting plate cutting plate coloured encrustation anterior plates

cutting plate on anterior

plates Maxillae black with black and? mostly light black, no brown, edges uniform light uniformly white edging?

paler bases white coloured white edging and sutures brown dark present

darker brown

Mx II – no. teeth (one 5+6 6 5 5+6 4+5 5–7 4 3 3–4 4 side)

(present

observations) continued next page