Leptestheria sarsi (Daday, 1923), 1997

Padhye, Sameer M. & Rabet, Nicolas, 2017, Re-description of two spiny clam shrimps (Crustacea: Branchiopoda: Spinicaudata) of the Indian subcontinent from Daday de Dees's collection at MNHN with new insights on the validity of Eulimnadia compressa (Baird, 1860) and Eulimnadia chaperi (Simon, 1886), Zootaxa 4294 (3), pp. 349-360 : 353-355

Leptestheria sarsi (Daday, 1923)

( Fig. 3 & 4 )

Leptestheriella sarsi Daday, 1923

Leptestheria sarsi Btrek, 1997 ; Rogers & Padhye, 2015

Material examined. MNHN-IU-2007-740 (= MNHN-Bp 457): Three males and two females

Locality. Gingi, Hindostan (Gingee, Tamil Nadu, India)

Description. Male. Head. Occipital condyle slightly produced, broader than long; occipital notch not distinct; ocular tubercle prominent; compound eyes about 0.3 times the size of ocular tubercle; ocellus not clearly seen; fornix prominent arising from dorsal angle of rostrum and overreaching the base of the compound eye; rostrum broad and spatulate, rostral spine not visible in the studied specimens, ( Fig. 3 A).

First antenna long, more than thrice the length of the base of second antenna; about 12–13 lobes present on the dorsal margin, each lobe lined with sensillae ( Fig. 4 C).

Second antenna peduncle cylindrical, lined with long transverse setae; exopod with 13 and endopod with 14 flagellomeres, each flagellomere bearing about 3–12 long posteriorly projecting spines with acute apices and plumose setae (5) on opposite sides ( Fig. 4 F).

Carapace oblong, anteriorly broad and tapering posteriorly; dorsal margin straight; ventral margin gently curved; umbone prominent; 20 or more distinct raised carapace growth lines and small rounded markings all over the shell. Reddish brown in coloration ( Fig.4 A).

Twenty six pairs of thoracopods, first and second thoracopod modified as claspers.

Clasper large; movable finger (endopod) broad at base, anteriorly narrowing and arched distally; tip distally with many small scales; large palp (endite V) two segmented in both claspers, both segments almost equal in length in the first clasper; distal palpomere (endite V outgrowth) about 0.6 times the proximal segment in second clasper; small palp (endite IV outgrowth) in both claspers cylindrical in shape, thrice as long as broad, directed slightly posteriorly in both claspers, their tips with small and slender setae; palm (endite IV) broadly rectangular, longer than broad; distinct medial broadly triangular protrusion at base of palm seen in both claspers; gripping area of the palm lined with spines increasing in size posteriorly, larger spines with acute apices ( Fig. 4 D & E).

Other thoracopods having similar structure as per genus; digitiform lobes on the exopodites; the last 5–8 pairs very small.

Abdomen. Segments 10/12–26 dorsally bear a group of long and slender posteriorly directed setae with acute apices, maximum of 5–8 setae seen per segment ( Fig. 3 D).

Telson rectangular, dorsal margin slightly arched, dorso-posterior tip slightly raised (one specimen); posterolateral ridge lined with 30–40 small spines of varying length, the spines on the dorso-posterior apex slightly recurved, ridge ending with a prominent spiniform projection, 0.4 times the length of the cercopods; its dorsal margin lined with fine serrated spines till about 2/3rd the length ( Fig. 3 C). Cercopods long, slightly arched, as long as dorsal margin of telson and reaching its spiniform projection; tips dorsally upturned ( Fig. 3 A); 3/4th of the dorsal margin lined with about 30–40 small spinulae; the remaining distal 1/4th lined with 6–8 long serrated spines medio-laterally, spines increasing in size distally, their length about 0.5–0.7 of the cercopod width at the thickest point ( Fig. 4 B).

Female. Carapace slightly smaller than male; rostrum triangular, rostral spine broken; occipital condyle as in male ( Fig. 3 B); thoracopods 9 and 10 with long epipodites for carrying eggs; dorsal edge of telson less convex than male; spines on the dorsal margin of telson slightly smaller than in male, cercopods as in male ( Fig.3 D).

Size. Male length: 10.8, 11.2 and 12.1 mm; height: 5, 5.2 and 5.5 mm respectively. Female length 9.2 & 10.2 mm; height: 4.6 & 5.2 mm respectively

Figures

FIGURE 3. Leptestheria sarsi (Daday, 1923). A, male head. B, female head. C, telson and cercopod (male). D, telson (female). E, dorsal armature. Scale bars: A & B: 0.5 mm; C & D: 0.75 mm; E: 0.05 mm.

FIGURE 4. Leptestheria sarsi (Daday, 1923). A, carapace. B, spines on postero-lateral ridge of telson. C, first antenna (male). D, clasper 1. E, clasper 2. F, single antennomere of second antenna. Scale bars: A: 1 mm; B: 0.05 mm; C – F: 0.2 mm.