Limnadiidae Baird, 1849

Padhye, Sameer, Rabet, Nicolas & Ghate, Hemant, 2015, First faunal inventory of large branchiopods (Crustacea: Branchiopoda) of Western Maharashtra, India with taxonomical and distributional comments, Zootaxa 3904 (2), pp. 208-222 : 215

Family Limnadiidae Baird, 1849

A single population of the genus Eulimnadia , Eulimnadia michaeli Nayar & Nair, 1968 has been reported from this region by Ghate et al. (2003). In our study, we were unable to find any Eulimnadia at that locality. However, E. indocylindrova Durga Prasad & Simhachalam, 2004 was seen in few other localities in the study area. Durga Prasad & Simhachalam (2004), had not elaborated much about the egg morphology which is the most diagnostic character for this genus ( Belk 1989, Rabet 2010). The authors also did not illustrate and comment on few details of other taxonomical traits such as the dorsal armature of the thorax and male thoracopod. In this regard, we describe in detail the egg morphology along with the above mentioned taxonomical characters of E. indocylindrova .

Material examined. Five females and two males Fifteen eggs from 4 of the 5 females used for SEM.

Description. Thorax. Eighteen-twenty pairs of thoracopods ( Fig.6 B). Dorso-posterior ridge lined with bunches of long setiferous setae of varying lengths ( Fig. 6 D). Seven to ten setae seen in the largest bunch ( Fig. 6 E). Size and number of setae diminishes towards the posterior end.

Male thoracopods. The first two thoracopods in male modified into claspers with an apical club (endite 4), a moveable finger (endite 5), and large (endite 6) and small palp ( Fig.7 A, B). Finger, arcuate in both claspers with a suctorial organ on their apices and lined with scales on the antero-ventral region ( Fig.7 D ‘star’); apical club broad with a low convex medial protrusion more distinct on the first clasper ( Fig.7 A ‘arrow’); apical field of the endite 4 of both claspers covered with stout triangular spines of similar size ( Fig.7 C) medially and bordered marginally with long, curved spines ( Fig.7 D ‘arrow’). Large palp of the first thorcapod 1.2 times the 5th endite in length, with its distal segment at least 1.1 times the proximal segment. Large palp of the second thoracopod more than twice as long as the 5th endite and its distal segment 1.3–1.4 times the proximal segment ( Fig.7 A, B). Distalmost region of the proximal segment of the large palp (at the point of articulation with distal segment) of second clasper lined with long setae ( Fig.7 B ‘arrow’). Apices of both the palps setulose.

Egg morphology. Cylindrical structure with a wider, inflated side creating a pentagonal shape, though in some orientations the eggs seem to be spherical. The furrows covering the main cylindrical part of the egg are parallel, but on the inflated side the furrows are randomly distributed. The furrow bottoms are narrow; the ridges are also narrow and more or less rounded. The surface is uniformly spongy with minute pores ( Fig. 8 : A–F). Length: 135–198 µm.

Remarks. The eggs of E. indocylindrova have the same general morphology like Eulimnadia geayi Daday, 1926 known from South America ( Pereira & Garcia 2001; Rabet 2010 & Rabet et al. 2012) and E. alluaudi Daday, 1926 from Madagascar ( Rabet, 2010 and references therein). However, egg surface of the E. indocylindrova is significantly different. Firstly, the depression in the eggs of this species is narrow as in E. alluaudi but not as in E. geayi . At the same time the ridge in the E. indocylindrova eggs is narrow like in E. geayi but not as in E. alluaudi .

Figures

FIGURE 6. Eulimnadia indocylindrova. A, Setule bunches (part) on the dorso-posterior ridge. B, Single bunch of setiferous setae on the dorsal posterior ridge (Scale bars: A – D: 0.1 mm)

FIGURE 7. Eulimnadia indocylindrova. A, Habitus. B, First clasper (arrow highlighting the medial protrusion). C, Second clasper (arrow highlighting the setae on the large palp proximal segment). D, Apical field and moveable finger (part) of the first clasper. E, Apical field and moveable finger (part) of the first clasper showing the longer spines on the apical field (arrow) and the scales on the moveable finger (star) (Scale bars: A 1 mm; B, E 0.1 mm)

FIGURE 8. Eulimnadia indocylindrova. SEM photographs. A – D, Egg shape. E, F, Egg surface (Scale bars: 0.05 mm).