Bioacoustics of Mursia aurorae

Description . Carapace transversely subovate, convex, 1.2 times as wide as long. Dorsal surface covered with closely spaced, small, flattened granules anteriorly, well spaced, larger granules posterolaterally; interspaced with prominently granular tubercles disposed in 7 radial rows. Mesogastric region highest part of carapace; cardiac, intestinal regions separated from branchial regions by deep, sinuous grooves. Anterolateral margin arcuate, with beaded line superimposed on nearly effaced tubercles. Lateral spine massive, one-third carapace width, dorsally granular, horizontal. Posterolateral margins oblique, sharply convergent, beaded line angled medially. Posterior carapace margin beaded, lateral teeth rounded. Front as wide as orbit, margin projecting beyond orbits, trilobate, median lobe broadly triangular, at lower plane than lateral lobes; lateral lobes rounded, separated from supraorbital margin by shallow concavity. Antennules obliquely folded. Supraorbital margin entire, minutely granular, with long plumose setae. Inner orbital tooth separated from outer orbital margin by deep U-shaped cleft, from front by orbital hiatus. Antennae small, slender, basal segment subrectangular, lodged in orbital hiatus. Eyes retractable, eyestalk short, granular, setose. Buccal frame rhomboidal, narrowing anteriorly. Thick fringe of plumose setae running length of third maxilliped exopod; merus, ischium granular, with short setae. Subhepatic canal oblique, subhepatic region granular, setose. Surfaces of thoracic sternum minutely granular. Chelipeds proportionally massive, granular, subequal. Merus distally bispinose, distal spine slender, acuminate, long, surface of proximal spine denticulate. External surface of chela convex, upper margin with dorsal crest bearing 8 denticles, successively larger distally. External surface of chela with 3 nearly effaced tubercules at base of crest, large rounded tubercles disposed in 3 diagonal rows, tubercles near lower margin of chela largest. Inner surface sparsely granular, with setose angled band near lower margin. Lower margin irregularly serrate, serrations successively smaller proximally. Upper margin of dactylus of larger chela crested, setose, proximally granular; with curved rounded tooth proximally fitting into depression formed between 2 molariform teeth in pollex; inner surface with stridulating ridge of 28 striae, larger medially. Smaller chela lacks large dactylar tooth, cutting edges of dactylus, pollex with triangular teeth. Pereiopods 2–5 slender, laterally compressed; upper, lower margins minutely granular; upper margin of carpus distally spinose; dactylus slender, longer than propodus, styliform. Male abdomen with somites 3–5 fused; prominent trilobate carina on second segment, triangular lateral lobes separated by wide clefts from lower, medially notched subrectangular median lobe; sixth abdominal segment subquadrate with sinuous lateral margins; telson forming equilateral triangle. G1 evenly tapered, curved distally, distally spinulose. G2 long, slender; cornute, distally hook-shaped. Colour . In life, dorsal surface of carapace and chelipeds pale pink, granules deep orange-red; lateral and meral spines darker distally, tips pale; pereiopods pale orange, colour slightly more intense distally on merus ( Fig. 1 ); ventral surfaces pinkish-white with flecks of black and red ( Fig. 2 C). Epistome with bright-red dots on each side of efferent channel ( Fig. 2 A, B). Outer surfaces of chelae orange with white tubercles ( Fig. 2 A); inner surface of palm with large, pale-centered red patch, distally near articulation with dactylus.