Marphysa gemmata Mohammad 1973
Creators: name: Katsiaras, Nikolaos
name: Simboura, Nomiki
name: Koutsoubas, Drosos
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Annelida
Polychaeta
Eunicida
Eunicidae
Marphysa
Marphysa gemmata

description: Marphysa gemmata Mohammad, 1973
Fig. 8 a–d, 9a–d, Table 2
Marphysa gemmata Mohammad 1973: 32, Figures 4–5
Material examined. Holotype (BMNH 1971.49), Kuwait, 9/05/1969, 1 specimen, 90 mm long and 3mm width, 165 segments with posterior end missing.
Description. Holotype an anterior fragment of about 165 segments (Fig. 9 a). Prostomium slightly incised, shorter than first peristomial ring, which is twice as long than second peristomial ring. 3 antennae and a pair of dorso-lateral palps present. Median antennae almost twice as long as the prostomium; dorso-lateral palps shorter. Antennae arranged in curved line and seem to be wrinkled, but possibly due to preservation. Eyes absent. Jaws removed. Maxillary formula (according to Mohammad, 1973): I(1+1), II(8+8), III(8+0), IV (8+10).
Dorsal cirri cirriform in anterior body (Fig. 8 a), more thin and slender after mid-body; almost twice as long (0.76 mm) as the parapodial lobe (0.32 mm) in anterior, increasing their length (1 mm) after first branchiae and remains at about this size. Ventral cirri tongue-shaped with rounded tips at the first 6–7 chaetigers, the tips bear a distal papilla in branchial segments (Fig. 8 a), which gradually gets less distinct after mid-body to finally have rounded tips in the posterior body. Ventral cirri (0.28 mm) shorter than dorsal cirri and almost as long as parapodial lobes, except of the posterior body where it is clearly longer. Post-chaetal lobe elongated and tongue-shaped in anterior and mid-body (Fig. 8 a); more than twice as long (0.24 mm) as acicular lobe in anterior segments, decreasing much in size to a similar length after the mid-body (0.12 mm to 0.05 mm). Pre-chaetal lobe is always truncated and straight. Branchiae present from 22 to 46 chaetiger; all pectinate and up to 18 filaments; always emerging from the same stem of dorsal cirri. Subcirral organs not distinct.
Superior setae in each fascicle consist of: (1) 3–4 long and slender capillaries, (2) 13–15 relatively shorter and slender capillaries, (3) 0–1 heterodont pectinate setae in anterior body (Fig. 8 c), rare, missing from posterior half of mid-body and towards the end (last observed at chaetiger 61); with 5–8 teeth, marginal teeth longer and unequal to each other (twice as long). Inferior setae consist only of composite falcigers, bidentate and hooded (Fig. 8 b, 9b). No composite spiniger present. Composite falcigers usually up to 35 per fascicle. In each fascicle of anterior body and branchial body, there are 3–4 falcigers with notably longer and thinner blades (up to 130 µm), very few also with bended tip, about one and half times longer than the others (up to 85µm). The length and the number of all setae decrease close to the posterior end. Aciculae blunt, pale yellow at the edge; 1–2 per parapodium. Acicular seta, beginning from about chaetiger 58 are pale yellow, hooded and bidentate; teeth have almost 90° angle between them; subdistal almost twice as wide (Fig. 8 d, 9c).
Remarks. Although the subcirral organs were not observed, there were described and illustrated in detail by Mohammad (1973) and so their low distinctness when re-examining the holotype should be a matter of preservation. This character should distinguish M. gemmata from the other species by contrast, but low distinctness of such organs could also apply for the rest of species that were preserved in the same method and such character could have been overlooked by past authors. In any case, additional differences of M. gemmata from the other species were found in the present study. M. gemmata differiates from M. purcellana also by a different shape of acicular setae (90° angle between teeth and subdistal twice as wide in M. gemmata., than 60° angle and subdistal only slightly wider in M. purcellana). The shape of acicular shape is similar to those of M. adenensis, but it differs from the latter also for having sparse distribution of pectinate setae in anterior body and completely missing from posterior body.
Distribution. Persian Gulf: Kuwait (Mohammad 1973).
Ecology. Sand substrate (Kuwait).
description: Published as part of Katsiaras, Nikolaos, Simboura, Nomiki & Koutsoubas, Drosos, 2014, The rare subgroup C 1 of Marphysa (Polychaeta, Eunicidae): re-description of species and first records in the Mediterranean Sea, pp. 201-217 in Zootaxa 3873 (3) on pages 211-213, DOI: 10.11646/zootaxa.3873.3.1, http://zenodo.org/record/228641