Four new species of the genus Rhopalophthalmus (Mysidacea: Crustacea) from the northwest coast of India Author Panampunnayil, S. U. Author Biju, A. text Journal of Natural History 2006 2006-10-18 40 23 - 24 1389 1406 http://dx.doi.org/10.1080/00222930600929301 journal article 10.1080/00222930600929301 1464-5262 4581324 Rhopalophthalmus murudana sp. nov. ( Figures 41–52 ) Material Holotype : adult male (IOBC-0505-10-50-1999). Allotype : adult female (IOBC-0505 A- 10-50-1999). Murud: (18 ° 16.39 9 –18 ° 18.30 9 N, 72 ° 55.28 9 –72 ° 59.72 9 E); March 1990 , six adult males, eight adult females, 13 immature males, six immature females, and nine juveniles. Description General form robust. Carapace anteriorly produced into broad triangular rostrum covering basal part of eye stalks; dorsal median nodules present. Eyes stout, as long as first antennular segment, cornea wider than stalk ( Figure 41 ). First segment of male antennule little longer than rest of peduncle, base of outer flagellum swollen and hirsute and all segments furnished with long plumose setae ( Figure 42 ). In female, peduncle longer and more slender than male, first segment 1.5 times longer than rest of peduncle. Antennal scale as long as antennular peduncle, five times as long as broad; antennal peduncle onethird length of scale; antennal sympod with two long and two short spines ( Figure 43 ). Figures 41–47. Rhopalophthalmus murudana sp. nov. (male, unless indicated). (41) Anterior part of body. (42) Antennule. (43) Antenna. (44) Third thoracic endopod. (45) Seventh thoracic endopod, distal part. (46) Eighth thoracic limb. (47) Eighth thoracic limb of female. Figures 48–52. Rhopalophthalmus murudana sp. nov. (male). (48) First pleopod. (49) Second pleopod. (50) Third pleopod. (51) Telson. (52) Posterior part of body. Mouthparts and first and second thoracic endopods as in R. mumbayensis . Third to seventh endopods slender, third with two, and fourth to seventh with three propodal segments ( Figures 44, 45 ). Eighth endopod three-segmented; second segment short with five long plumose setae on outer distal margin; third segment cylindrical and bent at right angle, with one stout seta at tip and two on inner margin, when straightened shorter than basal segment of exopod ( Figure 46 ). Eighth endopod in female unsegmented, straight, shorter than basal segment of exopod ( Figure 47 ). Pleopods in male biramous, first pleopod with unsegmented endopod and 10-segmented exopod ( Figure 48 ). Endopod of second pleopod 11-segmented; exopod long and 12- segmented, segments becoming longer posteriorly, distal segment with three long barbed setae ( Figure 49 ). Pleopods three to five with 10-segmented exopod and endopod ( Figure 50 ). In female, pleopods simple, unsegmented and rod-shaped becoming longer in posterior pairs. Telson 1.5 times longer than last abdominal somite, 2.7 times as long as broad at base, more than distal half of lateral margin armed with 15–16 slender spines gradually increasing in length distally, first two spines very small; inner pair of distal spines slightly longer than outer pair, subsidiary teeth becoming flattened distally ( Figure 51 ). Uropods longer than telson, two-segmented, endopod with stout spine on inner margin, exopod longer than endopod ( Figure 52 ). Length: adult male and female 8.5–9.3 mm . Etymology This species is named after the type locality. Remarks This species closely resembles R. orientalis , O. Tattersall. The vestigial endopod of the eighth thoracic limb, the number of carpopropodal segments of third to seventh thoracic endopods, and the spines on the telson are very similar in the two species. But in R. orientalis the rostrum is relatively low, eyes are longer, and the subsidiary teeth on the telson are broader and truncate. This species also resembles R. mumbayensis sp. nov. but differs in having fewer carpopropodal segments, spines on the lateral border of the telson are more slender and more in number, and the inner pair of distal spines on the telson are longer than the outer pair. Ecological note This species occurred in temperatures and salinity of 25.2–28.5 ° C and 35.7–36.3 psu, respectively, and was collected from 5 to 9 m depth where the bottom was clayey silt.