Marphysa fauchaldi, Glasby, Christopher J. & Hutchings, Pat A., 2010
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publication ID |
https://doi.org/ 10.5281/zenodo.193484 |
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DOI |
https://doi.org/10.5281/zenodo.5625708 |
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persistent identifier |
https://treatment.plazi.org/id/03A687D8-FFCC-D70C-0AC8-F68FFBC1F81E |
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treatment provided by |
Plazi |
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scientific name |
Marphysa fauchaldi |
| status |
sp. nov. |
Marphysa fauchaldi View in CoL n. sp.
Common name: Barra bloodworm ( Figs 1–3 View FIGURE 1. A − C View FIGURE 2. A − H View FIGURE 3. A − F )
Material examined. HOLOTYPE: Australia, Northern Territory, Ardatek Barrumundi farm, Cox Peninsula Road, off Elizabeth River, Darwin region 12.70313˚ S 130.96233 ˚E ( NTM W23040), coll. C. Glasby, 13 Dec. 2008. PARATYPES: same locality as for holotype, 1( BMNH ANEA 2010.1), 3( NTM W23041), 2( USNM 1133660), 4( NTM W23042), 1 specimen on several SEM stubs (AM W35419). NON-TYPES: Australia, Northern Territory, Ardatek Barramundi farm, Cox Peninsula Road, off Elizabeth River, Darwin region 12.70313˚ S 130.96233 ˚E several specimens ( NTM W17319), coll. C. Glasby, 27 Feb. 2002, Darwin, Stn LC1, 12˚24.8’S 130˚50.0’E Ludmilla Ck mouth, 1( NTM W68), mangrove mud, coll. R.J. Hanley, 26 Nov. 1981; Charles Darwin National Park, 1( NTM W18710), Stn E1-2-W-C2, 12˚27.389’S 130˚52.135’E, mud in Rhizophora zone, coll. K. Metcalfe, 15 Jan. 2003; East Arm Port, 1( NTM W18854), Stn DP-21-Q1, 1( NTM W18857), 12˚29.3’S 130˚ 54.18’E, coll. K. Metcalfe, 12 Oct. 2001; Mindil Beach, creek near casino, 1( NTM W20189), 12˚27’S 130˚50’E, coll. C. Glasby, 10 Sept. 2003; Cobourg Peninsula, Port Essington, Record Point, Stn NTERP, 1( NTM W20375), 11˚ 20.01’S 132˚ 10.70’S, coll. CSIRO CRIMP survey team, 23 Aug. 1998.
Comparative material. M. mullawa Hutchings & Karageorgopoulos, 2003 , Moreton Bay, paratypes 2(AM W27394−5); M. gravelyi Southern, 1921 , Rhomba Bay, Chilka Lake, India, paratype 1( BMNH 1938.5.7.55); M. borradailei Pillai 1958 , Sri Lanka, lectotype BMNH 1960.3.13.6; Marphysa elityeni Lewis & Karageorgopoulos, 2008 , Western Cape of South Africa. Marphysa furcellata Crossland, 1903 , town of Zanzibar and Zanzibar channel, Zanzibar, syntypes 2( BMNH 1924.3.1.139). Marphysa macintoshi Crossland, 1904 , east and west coasts of Zanzibar, syntypes 3( BMNH 1924:3:1:22−23). Marphysa simplex Crossland, 1903 , town of Zanzibar,, syntypes 2( BMNH 1924.3.1.1−2).
Measurements. Holotype, mature male, complete but fragmented into four parts, 424 chaetigers in total, about 190 mm long, 6.0 mm maximum width. Paratypes range in size from 78−155 mm long, 4.0− 5.5 mm maximum width, 225−415 chaetigers.
Description (of holotype, values for paratypes in parentheses). Body long and slender, initially cylindrical in cross-section but becoming slightly dorsoventrally flattened after first 6 or 7 chaetigers (6–10), more so in posterior body, which is coiled and fragile when preserved. Live worm, pink coloured with olive pigment, spotted white, dorsally on head and first 6 or 7 segments; prostomial appendages white, except at base which is also olive coloured ( Fig. 1A −C View FIGURE 1. A − C ).
Prostomium equal in length to first ring of peristomium mid-dorsally, appearing bilobed as buccal lips separated by deep ventral notch, continuing dorsally as narrow groove to base of median antenna ( Fig. 1A, B View FIGURE 1. A − C ). Eyespots not visible in holotype; in some paratypes small pair visible on prostomium at base of lateral antennae near border with peristomium. Prostomial appendages smooth (wrinkled in some paratypes), tapered to blunt point, arranged in shallow arc; median antenna equal in length, or slightly longer than (paratypes) lateral antennae; antennae longer than palps (1.2-1.3x) and about 2x (1.5−2.0x) length prostomium ( Fig. 1C View FIGURE 1. A − C ). Antennae and palps attached to prostomium by narrow peduncle ( Fig. 1A, C View FIGURE 1. A − C ). Mandibles dark, with lighter coloured cutting plates. Maxillary black, bases of Mx II–V paler; formula: I = 1 + 1, II = 5 + 6, III= 7 + 0, IV = 4 + 9, V = 1 + 1 (NTM W23041).
Parapodia similar throughout, comprising low, faintly bifid, prechaetal ridge and prominent rounded postchaetal lobe, conical dorsal cirrus and broader ventral cirrus: all three components extend laterally to about same level, except for first few chaetigers where parapodial lobe is shorter ( Figs 2A −H View FIGURE 2. A − H ). Branchiae arising from superior base of dorsal cirrus, beginning on chaetiger 31 (22−32) and extending posteriorly to last chaetiger (last to 10th last), up to 9 (6−9) pectinate filaments per branchia, best developed on mid-posterior body where they arch over dorsal surface for distance of 1/4−1/5 width of body ( Figs 2F −H View FIGURE 2. A − H ).
Chaetae arranged in two bundles separated by oblique row of aciculae, where maximally developed in anterior-mid body ( Figs 2C View FIGURE 2. A − H , 3B View FIGURE 3. A − F ). Supra-acicular bundle comprising 10−25 limbate capillaries (numbers reducing posteriorly) and 2−4 asymmetrically pectinate chaetae; subacicular bundle comprising up to 20 compound spinigers in anterior chaetigers and posteriorly to chaetiger 55 (13−42) after which they disappear, 10−20 limbate capillaries and single subacicular hook from chaetiger 40 (31−50) ( Figs 3 View FIGURE 3. A − F A-I). Supra-acicular limbate capillaries arranged in groups of two or three different lengths, but otherwise similar to each other and those of subacicular fascicle. Compound spinigers appear arranged in two groups each having slightly different blade length, but otherwise similar. Pectinate chaetae with long lateral teeth (about 2–3 times longer than inner teeth) show increasing teeth number, asymmetry and curvature posteriorly ( Table 1 View TABLE 1 ; Figs 3 View FIGURE 3. A − F G-I); also inner tooth closest to lateral tooth occasionally prolonged producing additional elongated lateral tooth ( Fig. 3 View FIGURE 3. A − F H). Posterior chaetigers with one or two types of pectinate chaetae: one with many small teeth (always present) and other with fewer larger teeth (sometimes present) ( Table 1 View TABLE 1 ; Figs 3 View FIGURE 3. A − F I). Subacicular hooks dark brown, bluntly pointed, bidentate, close-fitting hood ( Figs 3E, F View FIGURE 3. A − F ). Neuroaciculae black, maximally 4(3) in anterior chaetigers (chaetigers 8−15), reducing to 1 in posterior chaetigers. Notoaciculae slender and curved, pale, 3−4 at base of dorsal cirri from about chaetiger 30 onwards ( Figs 2F −H View FIGURE 2. A − H ).
Pygidium bearing two pairs of anal cirri on ventral margin; dorsal most pair about ½ to several times (in paratypes) length of pygidium, ventral most pair papilliform to ½ length (paratypes) of pygidium.
Variation. Size-dependent variation in both branchial and chaetal patterns has been reported before for Marphysa (e.g., Lu & Fauchald 1998). Although the number of specimens examined here was low (n = 9) and the size range small, we found the same strong size correlations as these authors, viz. larger specimens have branchiae that appear later, a higher number of branchial filaments, subacicular hooks that appear later; and compound spinigers that extend posteriorly over a greater number of chaetigers.
Remarks. In general appearance, Marphysa fauchaldi n. sp., may be distinguished from the other species of Marphysa occurring in Darwin Harbour ( M. mullawa and M. mossambica ) by its smaller size, smooth dorsal epithelium, and the marked flattening of body after the first 6–10 chaetigers. The other two species grow to a larger size, have a rugose, glandular dorsal epithelium, and posterior flattening is much more gradual over the anterior-mid body region. Specifically, the new species differs uniquely from other Group B2 Marphysa species in having fewer compound spinigers, which are present over a smaller range of chaetigers (first 13−55 chaetigers only). Also, the compound spinigers are accompanied by limbate capillaries in the subacicular bundle of the anterior parapodia; initially the compound spinigers out-number the capillaries, but they are gradually replaced by the capillaries until from the anterior-mid body onward only capillaries are present. In this respect the species is approaching the condition of M. mossambica , which completely lacks compound chaetae. The other difference between M. fauchaldi n. sp. and other B2 species is the presence of pectinate chaetae from chaetiger 1, and that they do not exceed 2−4 per bundle (because of this and their small size they are difficult to observe under the compound microscope).
Etymology. The new species is named after Kristian Fauchald, friend and mentor. The common name, ‘Barra’, is the local name for Barramundi.
Distribution. Northern Australia, including Darwin Harbour and Cobourg Peninsula, Port Essington.
Biology. Densities and distributions of M. fauchaldi n. sp., in the aquaculture ponds varied considerably depending on the species farmed. When Tiger Prawns, Penaeus monodon , were present densities were low as a result of predation, and the worms occurred mainly in deep burrows in the clay banks; when Barramundi, Lates calcarifer were present densities were very high (of up to 900 individuals per square metre) and the worms appeared to be evenly distributed over the floor of the pond, although this needs further study. Marphysa fauchaldi n. sp., encapsulates its embryos and larvae in jelly cocoons ( Table 2), which seems to be an adaptation for life in unstable estuarine environments. Details of its ecology and biology including larval development and growth are currently being investigated (Glasby et al. in prep.).
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