Nasima Manning 1991
Creators: name: Ng, Peter K. L.
name: Rahayu, Dwi Listyo
name: Naser, Murtada D.
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Camptandriidae
Nasima

description: Nasima Manning, 1991
Nasima Manning, 1991: 304. —Ng et al. 2008: 233.
Type species. Cleistostoma dotilliforme Alcock, 1900, by monotypy.
Diagnosis. Carapace average width to length ratio 1.44; subquadrate, moderately convex; regions of dorsal surface well developed, distinct, gastro-cardiac groove distinct, shallow; surface sparsely hairy, dorsolateral margin distinctly demarcated as raised row of granules; anterolateral margin with low, blunt lobe behind external orbital tooth; epigastric lobes present (Figs. 5, 6 A). Front with broad, shallow groove medially on dorsal surface, with thickened margin; frontomedial margin bilobed (Fig. 6 A). Supraorbital margin gradually curved, junction between base of front and supraorbital margin gradual, not sharply demarcated (Fig. 6 A); infraorbital margin straight along inner portion, outer portion concave, inner infraorbital tooth triangular, with rounded apex, not very distinctly separated from rest of infraorbital margin. Posterior edge of epistome thick, posterior medial tooth broadly triangular (Fig. 6 B). Third maxilliped with Yshaped groove on surface; pterygostomian region with closed, shallow Y-shaped sulcus (Fig. 6 C). Chelipeds small, equal, similar in both sexes, tips spatulate, setose (Fig. 6 D, E). Meri of ambulatory legs foliaceous; anterior margins of carpus, propodus with dense seate; P3, P4 ventral margins lined with short sharp spines (Fig. 5). Male abdomen narrow, somite 1 about as narrow as somite 2, not reaching P5 coxae; somite 5 not constricted, somites 2–5 fused, sutures between somites 3, 4 interrupted very faintly, visible as short lateral grooves, median transverse grooves, somites 4, 5 separated by distinct groove but immobile, somite 6 with limited mobility with somite 5; telson free (Fig. 6 F); female with subcircular abdomen; somites 1–6, telson free. G1 recurved, lacking distal process, outer edge of recurved portion broadened to form low but distinct flat lobe halfway to tip, apex conical (Fig. 6 G, H).
Remarks. Manning (1991) established Nasima for Cleistostoma dotilliforme Alcock, 1900. He distinguished it from other genera mainly by the male abdomen having all six somites and telson free, and the chelipeds being of similar size in both sexes. Not all the somites of the male abdomen are actually free, however, although some of the sutures separating them remain visible; somites 2–5 are actually immobile. Somites 2-4 have only a shallow and barely discernible suture separating each other; while the suture between somites 4 and 5 suture is complete, though immobile (Fig. 6 F). Somites 5 and 6 are also barely mobile, even if the suture is complete and appears deep. Manning (1991) also diagnosed the genus as having the meri of the ambulatory legs without spines, but this is not completely correct since the ventral margins of meri of the P3 and P4 have numerous sharp granules that resemble short spines (Fig. 5). The lack of sexual dimorphism in the chelipeds is, however, useful, and several other characters, in addition to those mentioned by Manning (1991), make Nasima generically distinct from Cleistostoma.
Nasima dotilliformis differs from C. dilatatum (type species of Cleistostoma) in several key characters. The male abdominal somite 1 of C. dilatatum is transversely elongated, with the ends overreaching the P5 coxae (Fig. 10 A). In N. dotilliformis, male abdominal somite 1 is only almost as transversely wide as somite 2 and the ends before the P5 coxae (Fig. 10 C). The apex of the G 1 in C. dilatatum is drawn out to form a point, with subapical mushroom-like tubercles on one edge (Fig. 11 E, F). The apex of the G 1 in N. dotilliformis, on the other hand, is conical and lacks mushroom-like tubercles (Fig. 6 G, H). In addition, the low lobe present on the recurved portion of the G 1 in N. dotilliformis (Fig. 6 G, H) is absent in C. dilatatum (Fig. 11 E, F). The sexual dimorphism of the chelipeds is very evident in adult C. dilatatum but is not apparent in N. dotilliformis (Fig. 5). The first sternite of the thoracic sternum in N. dotilliformis has a rounded anterior edge (Fig. 10 C) while the same structure in C. dilatatum is broadly triangular (Fig. 10 A). Furthermore, the carapace anterolateral margin in C. dilatatum is entire but in N. dotilliformis, there is a small lobe present just behind the external orbital tooth (Figs. 5, 6 A). These observations support Manning's (1991) action of establishing Nasima.
The relationship of Nasima with Leptochryseus Al-Khayat & Jones, 1996, however, is problematic. This affinity has never been discussed before, even when Leptochryseus was first described, but this may have been because several of the diagnostic features were misinterpreted by Al-Khayat & Jones (1996) (see discussion for this genus later). It is noteworthy that Nasima shares the diagnostic male abdominal and thoracic sternal generic characters of Leptochryseus (Jones & Clayton, 1983) (Figs. 6 F, 7C, 9B, 10B, C). The G1s of Nasima and Leptochryseus are also very similar (Figs. 6 G, H, 11K, L), and there are no significant differences, certainly not at the genus level. The ambulatory legs of Nasima and Leptochryseus are also very similar, sharing the armature along the ventral margins of the P3 and P4 meri (spines relatively weaker in Nasima) with prominent tufts of setae on the propodus (Figs. 5, 7 A, 8). The carapaces of the two species are also similar, the only major differences in their relative proportions, the carapace of Nasima being almost always transversely rectangular and relatively broader (average width to length ratio 1.43, versus 1.32 in Leptochryseus). The carapace regions of Nasima are also relatively more developed and pronounced, with scattered groups of granules (Fig. 5), while in Leptochryseus, the regions are lower and less distinct, with the granules much smaller (Figs. 7 A, 8). The anterolateral margins also differ; those of Nasima always have a low but visible lobe behind the external orbital tooth (Fig. 5, 6 A), while in Leptochryseus, the anterolateral margin is entire and never develops a tooth or lobe, although the area just behind the external orbital tooth may be crenulated or uneven. This character may not be reliable once a larger series of specimens can be examined. The likelihood that both genera are synonymous is high, but the lack of sexual dimorphism in the chelipeds of Nasima (distinct in Leptochryseus), the presently observed differences in carapace shape and ornamentation, and the presence of a low anterolateral lobe in Nasima (absent in Leptochryseus) suggest that it is best to separate them for the moment. In addition, it is clear that Nasima dotillifomis is a smaller-size species, with females maturing and bearing eggs less than 10 mm in carapace width. In contrast, females of L. kuwaitensis 25 mm in carapace width do not appear to be fully mature. The few differences observed here do not appear to be very significant and key to resolving the question of whether these two genera are distinct may be in obtaining a much larger series for L. kuwaitensis.
description: Published as part of Ng, Peter K. L., Rahayu, Dwi Listyo & Naser, Murtada D., 2009, The Camptandriidae of Iraq, with description of a new genus and notes on Leptochryseus Al-Khayat & Jones, 1996 (Crustacea: Decapoda: Brachyura), pp. 1-26 in Zootaxa 2312 on pages 11-14, DOI: 10.5281/zenodo.191909