Marphysa Quatrefages, 1865

Glasby, Christopher J. & Hutchings, Pat A., 2010, A new species of Marphysa Quatrefages, 1865 (Polychaeta: Eunicida: Eunicidae) from northern Australia and a review of similar taxa from the Indo-west Pacific, including the genus Nauphanta Kinberg, 1865, Zootaxa 2352, pp. 29-45 : 30-32

Marphysa Quatrefages, 1865

Common name: Bloodworm

Marphysa Quatrefages, 1865: 331 .

Nauphanta Kinberg, 1865: 564 . – Fauchald, 1987: 375.

Diagnosis (after Fauchald et al. 2003). Anterior body segments cylindrical, usually becoming dorsoventrally flattened posteriorly; epidermis iridescent anterodorsally. Prostomium with deep or faint anteroventral notch which may give it a bilobed appearance; bearing five similar-looking appendages—three antennae and two (lateral) palps arranged in more or less curved line near posterior edge. Eyespots present or absent. Peristomium divided into two rings, anterior one longer than posterior one; peristomial cirri absent. Branchiae present over most of body or restricted to anterior half, pectinate or palmate arrangement. Chaetae include in superior position, limbate capillaries and pectinate chaetae which may be symmetrical or asymmetrical, and in inferior position, compound falcigers (may be absent), compound spinigers (rarely absent) and subacicular hooks. Jaw apparatus includes ventral mandibles and dorsally, maxillae comprising short, winged, or slender, carriers and four paired (and one unpaired) maxillary plates.

Remarks. Fauchald (1987) resurrected the genus Nauphanta to accommodate two species lacking compound falcigers and compound spinigers, including N. novaehollandiae Kinberg, 1865 , originally from Sydney Harbour, and Eunice mossambica Peters, 1854 originally from Mozambique. He considered Nauphanta to differ from Marphysa in having a unique type of chaeta present only in posterior chaetigers, ‘fan chaetae’, or ‘asymmetrical pectinate chaetae’ as they are referred to here. However, our observations suggest that fan and pectinate chaetae are both in the same position in the neuropodium—on the anteromedial edge of the supra-acicular bundle of chaetae—so it is highly likely that the two types of chaetae are homologous. Further, present observations on Marphysa fauchaldi n. sp. ( Table 1 ) and those of Crossland (1903: 140) and Treadwell (1922: 152) indicate that asymmetrical pectinate chaetae are not restricted to posterior chaetigers but may occur also in more anterior chaetigers. In Marphysa fauchaldi n. sp., as in other species of the genus with asymmetrical pectinate chaetae (see Table 2), asymmetry becomes more pronounced in posterior pectinate chaetae. The presence of pectinate chaetae is best determined by use of SEM, but they are also readily visible under high powered light microscopy provided the parapodium is mounted anterior side up.

The only other differences between Nauphanta and most Marphysa are the absence of both compound falcigers and spinigers in the former. The absence of compound falcigers is probably an ontogenetic loss as species of Marphysa whose embryology and juvenile development has been investigated have this type of chaetae initially as juveniles, but they are replaced in adults ( Borradaile 1901; Southern 1921; Aiyar 1931, Pillai 1958; pers. obs. CG). The absence of compound spinigers is likely to be paedomorphic because juveniles of several Marphysa species, for example M. borradailei (see Pillai 1958), lack compound spinigers but they develop later in adults. Therefore continued absence of this type of chaetae in adults can be viewed as a retained juvenile characteristic. The new species described here, M. fauchaldi n. sp., exhibits what might be called ‘partial paedomorphosis’ in which compound spinigers are absent in all parapodia except the anterior ones (see below). Therefore, the absences of both types of compound chaetae in Nauphanta are most likely attributable to development novelties restricted to this particular taxon (here considered to represent a single species), rather than synapomorphic characteristics of a group of species—thus we propose returning Nauphanta to junior synonymy with Marphysa .

Species included. Two of the species of Marphysa described below ( M. mullawa and M. fauchaldi n. sp.) are closest in morphology to Group B2 of Fauchald (1970), that is, having compound spinigers only and branchiae present to the end of the body. The only other species listed as Group B2 Marphysa reported from Australia is M. macintoshi , originally described from Zanzibar. However, Group B2 is well represented in the tropical/subtropical Indo-Pacific waters by many other species including M. gravelyi Southern, 1921 (type locality, Chilka Lake, India), M. orientalis Treadwell, 1936 ( China) , M. tamurai Okuda, 1934 ( Japan) , M. teretiuscula ( Schmarda, 1861) ( Sri Lanka) and M. borradailei Pillai 1958 ( Sri Lanka). Marphysa borradailei was classified as Group C2 (only compound falcigers present) by Fauchald, presumably because falcigerous chaetae are mentioned in Pillai’s description (p. 104), but the chaetae illustrated by Pillai are clearly compound spinigers, albeit with short blades. Marphysa sanguinea ( Montagu, 1813) is also a Group B2 species, but Australian records of this species are all thought to be misidentifications, having been described as a new species, M. mullawa Hutchings & Karageorgopoulos, 2003 .

Day (1962) regarded Marphysa simplex Crossland, 1903 and M. furcellata Crossland, 1903 to be junior synonyms of M. macintoshi Crossland, 1903 —all three species having Zanzibar as the type locality. The main difference between the three species—whether or not an anterior notch exists between the two globular buccal lips—was attributed by Day to intraspecific variation. Examination of the types of all three species together with the hundreds of specimens of M. fauchaldi n. sp., suggest that the form of the prostomium does not vary significantly between individuals, and this taken together with the other small, but significant, differences between the three species suggest that M. simplex and M. furcellata are each diagnosable, as indicated in the Key. However Marphysa simplex is considered here to be a junior synonym of M. teretiuscula (the possibility was considered likely by Crossland (1903: 136)) as both species present the unusual condition of having a more or less circular (in cross section) body along the entire length of the worm, and antennae are all approximately the same length, being twice the length of the prostomium (see Key). Notwithstanding the relegation of M. simplex to junior synonymy, the name still remains a secondary homonym of Marphysa simplex Langerhans, 1884 (as Amphiro simplex ) from Madeira.

Tables

TABLE 1. Morphometric data on the pectinate chaetae of Marphysa fauchaldi n. sp. based on SEM micrographs of paratype (AM W 35419).

Chaetiger region (number pectinate chaetae observed)	No. teeth (excluding two lateral ones)	Teeth—form	Lateral teeth length: medial teeth length (mean ratio)	Asymmetry (degree)	Curvature (degree)	Width distally: width at shaft (mean ratio)	Additional long tooth, presence (p) or absence (a)
1–15 (1)	14	moderately acuminate	?	slight	slight	4.17	a
13 (2)	10–11	slightly acuminate	2.14	slight	slight	?	p
21 (1)	15	moderately acuminate	2.26	slight	moderate	4.00	p (Fig. 3H)
21(1)	10	slightly acuminate	2.42	mod	mod	?	p
41–70(1)	~10	slightly acuminate	2.56	mod	mod	?	a
101–130 (1)	~19	moderately acuminate	2.20	high	high	4.58	?
131–160 (2)	19–22	highly acuminate	3.35	high	high	4.28	p
161–190 (3)	22–31	highly acuminate	1.83–2.66	high	high	4.21	a
221–250 (2)	28–29	highly acuminate	~3.22	high	high	5.4	a
251–266 (1)	29	highly acuminate	~2.6	high	high	?	a
281, 282 (3)	23–25	highly acuminate	2.00– 2.60	high	high	4.43	p