Bioacoustics of Persianorchestia nirvana

Description. Based on holotype , male, 10 mm , INIOC 1-2S. Eyes present, well developed, about 2/3 of head length. Antenna 1 short almost reaching end of peduncular article 4 of antenna 2. Antenna 2 shorter than half body length; peduncular articles slender with many small robust setae, article 5 the longest; flagellum with 19 articles, final article large, cone-shaped, virgula divina present. Upper lip with apical setal patch; epistome with robust setae. Lower lip distolateral setal tuft absent, with vestigial inner plates. Mandible left lacinia mobilis 5-cuspidate. Maxilla 1 with small palp, 1-articulate; inner plate with two plumose setae; outer plate with 9 dentate setae. Maxilliped palp article 2 distomedial lobe well developed; article 4 small, button-shaped. Pereon . Gnathopod 1 sexually dimorphic; parachelate; coxa smaller than coxa 2, anteriorly produced; posterior margin of carpus and propodus each with lobe covered in palmate setae, palmate lobes in male only; carpus longer than propodus, 1.6 × as long as propodus, 1.9 × as long as broad; propodus subrectangular, anterior margin with 5 groups of about 11 robust setae, medial surface with 9 cuspidate setae; palm with 3 serrate setae, palm obtuse, without spine patch on posterodistal corner; dactylus longer than palm, simplidactylate, without anterodistal denticular patch. Gnathopod 2 sexually dimorphic; subchelate; basis slender; ischium with weak rounded lobe on mid-anterior margin, without anterodistal lobe on medial surface; posterior margin of merus, carpus and propodus each without lobe covered in palmate setae; carpus triangular, posterior lobe absent, not projecting between merus and propodus; propodus subovate, 1.6 × as long as wide, palm acute, smooth, with proximally protuberance, covered with robust setae; dactylus shorter than palm, broadly curved, without anteroproximal bump, posterior margin without proximal sinus. Pereopods 3–4 coxae as wide as deep. Pereopods 3–7 cuspidactylate; dactyli without anterodistal patch of many rows of tiny setae. Pereopod 4 as long as third pereopod. pereopod 5 propodus 1.1 × long as carpus. Pereopods 6–7 not sexually dimorphic. Pereopod 6 shorter than pereopod 7; coxa rounded, with 1 marginal seta. Pereopod 7 basis without lateral sulcus, posterodistal lobe present; merus and carpus slender and extended. Pleon . Pleopods 1–3 biramous, all well developed. Pleopod 1 peduncle with 8 setae on outer margin and 1 medio-facial seta. Pleopod 2 with 10 setae on outer margin and 3 medio-facial setae. Pleopod 3 peduncle outer margin with 7 setae and 5 medio-facial setae. Epimera1 –3, without stridulating organs, posteroventral corner with small subacute spine, ventral margin smooth. Epimeron 2 subequal in length to epimeron 3. Uropod 1 peduncle with 10 robust setae; rami with apical spear-shaped setae, inner ramus slightly shorter than outer ramus, inner ramus with 6 marginal robust setae in a row; outer ramus slender, without marginal robust setae. Uropod 2 not sexually dimorphic; rami with apical spear-shaped setae, inner ramus slightly shorter than outer ramus, with 10 marginal robust setae; outer ramus with 2 marginal robust setae in 1 row, inner ramus with 4 marginal robust setae. Uropod 3 well developed; peduncle with 4 robust setae; ramus subequal in length to peduncle, with 3 marginal robust setae, and 4 apical setae. Telson apically incised, with 5–6 robust setae per lobe. Female (sexually dimorphic characters). Based on paratype , female, 7 mm , INIOC 2-2S. Antenna 2 less than half body length; peduncular article 5 subequal to article 4 in length. Gnathopod 1 simple; posterior margin of merus, carpus and propodus each without lobe covered in palmate setae; carpus 2.5 × as long as broad; propodus anterior margin with 3groups of 6 robust setae. Gnathopod 2 mitten-shaped; basis not expanded; ischium without lobe on anterior margin; posterior margin of carpus and propodus each with lobe covered in palmate setae; carpus well developed (not enclosed by merus and propodus), posterior lobe present, projecting between merus and propodus; propodus 2.5 as long as wide, palm obtuse; dactylus shorter than palm, straight, posterior margin smooth, not modified distally, blunt. Oostegites longer than wide (length greater than 2 × width), weakly setose (14–18), setae with simple smooth tips.