Marphysa purcellana Willey, 1904
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publication ID |
https://doi.org/ 10.11646/zootaxa.3873.3.1 |
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publication LSID |
lsid:zoobank.org:pub:022136BF-394F-4959-8CE7-1F4971923223 |
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DOI |
https://doi.org/10.5281/zenodo.5613407 |
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persistent identifier |
https://treatment.plazi.org/id/03A75B37-910D-FFFC-07DB-F990FC6A7FE8 |
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treatment provided by |
Plazi |
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scientific name |
Marphysa purcellana Willey, 1904 |
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Marphysa purcellana Willey, 1904 View in CoL
Fig. 6 View FIGURE 6 a–h, 7a–d, Table 2 View TABLE 2
Marphysa purcellana Willey 1904: 263 View in CoL , Plate 13 Figure 17; Day 1953: 435; Day 1960: 335; Day 1963a: 408; Day 1967: 397, Figures 17.6k–o
Material examined: Type ( BMNH 1911.2.1.13), Table Bay, 1904, 1 specimen, 95mm long and 5mm width, complete; Mounted Slides from same type ( BMNH 1911.2.1.49–52).
Description. Prostomium bilobed anteriorly, slightly longer than first peristomial ring, which is almost four times longer than second peristomial ring ( Fig. 7 View FIGURE 7 a). Three antennae and a pair of dorso-lateral palps present. Antennae are slightly shorter than the prostomium; median antenna shorter than the laterals. Antennae arranged in line and seem to be wrinkled, but possibly due to preservation. Eyes present, positioned posteriorly to the two lateral antennae and covered by the peristomial ring. Maxillary formula: I(1+1), II(5+5), III(5+0), IV (3+8).
Dorsal cirri cirriform in anterior body, more thin and slender after mid-body; slightly longer than parapodial lobe in anterior, increasing their length (1.24 mm) up to about three times as long in branchial region ( Fig. 6 View FIGURE 6 a) and gradually decreasing again posteriorly ( Fig. 6 View FIGURE 6 e). Ventral cirri tongue-shaped with rounded tips at the first 6–7 chaetigers, the tips bear a distal papilla in branchial segments ( Fig. 6 View FIGURE 6 a), which gradually gets less distinct after midbody to finally have rounded tips in the posterior body ( Fig. 6 View FIGURE 6 e). Ventral cirri (0.6 mm) shorter than dorsal cirri and almost as long as parapodial lobes throughout. Post-chaetal lobe elongated and tongue-shaped in anterior and midbody ( Fig. 6 View FIGURE 6 a); more than twice as long as acicular lobe in anterior segments, decreasing much in size to a similar length after the mid-body ( Fig. 6 View FIGURE 6 e). Pre-chaetal lobe always truncated and straight. Branchiae ( Fig. 6 View FIGURE 6 a) present from 8 to 28 chaetiger; all pectinate and always emerging from the same stem of dorsal cirri. First branchiae with 4 filaments, gradually increasing up to about 18 filaments and length (1.58 mm) a bit longer than dorsal cirri and then decreasing again down to 11 filaments at the last branchiae.
Superior setae in each fascicle consist of: (1) 3–4 long and slender capillaries, (2) 9–11 relatively shorter and slender capillaries, (3) 1–2 heterodont pectinate setae in anterior body, up to 12 in posterior body ( Fig. 6 View FIGURE 6 h); marginal teeth longer and unequal to each other (twice as long) throughout the body, with 8–12 teeth in anterior region ( Fig. 6 View FIGURE 6 f), increasing up to 20 in posterior half of mid-body ( Fig. 6 View FIGURE 6 g, 7c). Inferior setae consist only of composite falcigers, bidentate and hooded ( Fig. 7 View FIGURE 7 b). No composite spiniger present. Composite falcigers usually up to 16 per fascicle, more than 30 present at the branchial region. Towards the posterior body, the number and length of all setae decreasing, except of pectinate that increases. The length of the falciger blades is mediocre (40–56µm) and about equal between falcigers of the same fascicle in most of the body ( Fig. 6 View FIGURE 6 c), except of branchial region where a few falcigers have blade-length more than twice as long as the others ( Fig. 6 View FIGURE 6 b, 7b). Aciculae blunt, dark with pale tips, 3 per parapodium until mid-body ( Fig. 6 View FIGURE 6 e); but only 2 towards the posterior end. Acicular setae light brown, bidentate, teeth have about 60° angle between them, subdistal tooth slightly wider than distal tooth ( Fig. 6 View FIGURE 6 d, 7d).
Distribution. South Africa: Table Bay ( Willey 1904); Mossel Bay, Algoa Bay, False Bay, South Coast ( Day 1960); Orange River estuary ( Day 1963a).
Ecology. Kelp forests of Ecklonia maxima ( Willey 1904) ; Sand with shells, coralline algae, rocks and stones ( Day 1960).
Remarks. Marphysa purcellana original description was very brief and without adequate figures. The differentiation from M. adenensis was based only on the shape of the prostomium (bilobed, rounded in M. adenensis ), the length of the median antennae (shorter than the prostomium, rather than longer) and the starting point of branchiae (8th chaetiger, instead of 15). However, the anterior shape of the prostomium has been found to vary even in the same species ( Fauchald 1970), the antennae are often lost or incomplete and the first branchial segment could be age-specific. Day (1934) concluded at first, that it must be a synonym of M. adenensis , but after a personal examination of the type ( Day 1953), he re-enacted it to a distinct species. On the differential characters, he also added the shape of acicular setae, without any other details, probably observing a vertical angle between the teeth and a much wider sub-distal tooth in M. adenensis , as also confirmed in the present re-examination of the type-materials. Another important difference, suggested by the present study, should be the increasing number of pectinate setae (up to 12) in half mid-body and towards the posterior end in M. purcellana (1–2 along the body in M. adenensis ) and the higher teeth number of the pectinate setae (8–12 in anterior and 18–20 in posterior body in M. purcellana , instead of 4–6 and 7–8 respectively in M. adenensis ).
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
