Bioacoustics of Ciliopagurus grandis

Description . Cephalothorax ( Fig. 1 A, B) fairly depressed dorsoventrally. Shield ( Fig. 2 A) about 1.1 times longer than broad; anterolateral margins sloping; anterior margin between rostrum and lateral projections very slightly concave; posterior margin roundly truncate; dorsal surface flat, with scattered shallow pits anterolaterally and few tufts of stiff setae laterally; Y-shaped decalcified suture present posteriorly. Rostrum obtuse, rounded, slightly exceeding lateral projections. Lateral projections also obtuse, unarmed. Ocular peduncles ( Fig. 2 A) equal in length, long and slender, 0.8 times as long as shield and 7.0–7.5 times longer than corneal width, cylindrical, slightly inflated basally and not dilated in corneal region; dorsal surfaces with scattered very short setae. Ocular acicles narrowly triangular, mesial margins nearly straight, lateral margins sloping, terminating in small marginal spine; narrowly separated basally (distance between acicles less than half width of 1 acicle). Antennal peduncle ( Fig. 2 A) moderately long. Ultimate segment reaching corneal bases, 0.4–0.5 times as long as shield and about twice length of penultimate segment, dorsally with scattered minute setae. Penultimate segment with several short to moderately short setae. Basal segment short; ventrodistal margin produced in triangular process; laterodistal margin denticulate; lateral surface unarmed or armed with minute spinule dorsally. Antennal peduncles ( Fig. 2 A) reaching distal one-fourth to one-fifth of ocular peduncles. Fifth segment slightly flattened dorsoventrally, with scattered tufts of very short setae. Fourth segment unarmed or armed with minute spine dorsodistally, with short setae. Third segment with small spine at ventrodistal angle and some tufts of setae. Second segment with dorsolateral distal angle produced, terminating in simple or bifid spine, lateral margin unarmed; dorsomesial distal angle with minute spinule, mesial margin with stiff setae. First segment almost concealed by anterolateral margin of branchiostegite; ventrodistal margin with 1 minute spine lateral to antennal gland opening. Antennal acicle ( Fig. 2 B) reaching proximal two-fifths of ocular peduncle, terminating in acute, simple or bifid spine; mesial margin with 1 or 2 tiny spines or spinules, lateral margin unarmed or 1 tiny spine. Flagellum slightly overreaching chelipeds; each article with some minute setae ( third> second); each exopod well developed, while endopods greatly reduced, 0.2–0.3 length of exopods. Female with 4 biramous unpaired pleopods, with both rami multi-segmented and well developed. Uropods asymmetrical. Sixth pleonal tergite ( Fig. 2 I) about 1.5 times longer than broad, divided into two parts by distinct transverse groove across at posterior two-thirds; lateral indentations deep, narrow; posterior part with shallow median groove, posterolateral margins unarmed. Telson ( Fig. 2 J) with posterior lobes broadly and roundly subtriangular, greatly unequal (left much larger than right), with narrow, deep median cleft; terminal margins unarmed, but with row of moderately long stiff setae. Coloration in formalin . ( Fig. 1 A, B). Shield orange, anterior margin whitish. Posterior carapace pale orange; branchiostegite and ventrolateral portion of posterior carapace crimson. Ocular peduncle white on dorsal face, otherwise red. Antennular and antennal peduncles whitish, antennal flagellum uniformly pale orange. Chelipeds and ambulatory legs generally orange, transverse ridges lined by red. Pleon generally white, without markings; sixth somite, telson and uropods orange. Claws of chelipeds and ambulatory legs and corneous spinules on ambulatory dactyli black or dark brown. See Fig. 1 A, B. Housing . Using gastropod shells, e.g., Xenophora solaris (Linnaeus, 1767) (Discopoda: Xenophoridae ), Ficus gracilis (Sowerby, 1825) and F. ficoides (Lamarck, 1822) (Discopoda: Ficidae ).