Miscellanea Zoologica Hungarica 11. 1997 (Budapest, 1997)

Hołyńska, M.: A new representative of Mesocyclops thermocyclopoides-circle (Copepoda: Cyclopoida) from India

Variability Variability of body length and ratios is shown in Table 3. Table 3. Morphometrical variability of Mesocyclops dadayi sp. n. (in parentheses the numbers of specimens measured). Range Average Total length (12): 940-1060 pm 982 pm Cephthx 1/w (9): 1.05-1.16 1.12 Gen dos 1/w (10): 1.05-1.41 1.27 Pros/Uros (10): 1.49-1.78 1.59 P4 enp3 1/w (12): 2.39-2.76 2.60 ap sp, in/out (12): 1.10-1.31 1.22 in ap sp/ enp3 1(12): P5 0.90-1.03 0.97 in exp s/basend s (4): 0.74-1,35 1.14 Furca 1/w (10): 3.16-3.61 3.35 Furcal s ter accès (5): 175-195 pm 187 pm in ter (5): 365-380 pm 375 pm out ter (5): 255-270 pm 263 pm post lat (5): 65-70 pm 69 pm Ant lat s/furca 1 (7): 0.38-0.49 0.43 Dors s/post lat s (6): 1.24-1.72 1.43 In ter s/Uros (5): 0.94-1.03 1.00 Abbreviations: cephthx = céphalothorax, 1 = length, w = width, gen dos = genital double somite, pros = prosome, uros = urosome, P4 = leg 4, enp3 = third segment of endopod, ap = apical, sp = spine, in = inner, out = outer, P5 = leg 5, exp = exopod, s = seta, basend = baseoendopod, ter = terminal, accès = accessory, post = postera-, lat = lateral, ant = antero-, dors = dorsal Retaining the basic pattern of the spinule ornamentation of the antennary basis, the number of spinules changes in certain groups (e. g. 10-17 and 20-26 spinules in the longitudinal rows on the caudal and frontal surface respectively). Caudal group of tiny spinules next to distal rim (Fig. II) is absent in 3 of 12 specimens on both antennary basis. Variability in the armature of P4 intercoxal sclerite and coxa, the curvature and banding of the copulatory duct see in Fig. 3F-L. The light microscope observations suggest that the number of circular pores posterior to the copulatory pore also changes from 0 to 2 (Fig. 3C, K, L). Diagnosis Mesocyclops dadayi sp. n. differs from other members of the Thermocyclopoides-ckclc by the following combination of the characters: caudal spinule ornamentation of the antennary