Bioacoustics of Nuuanu jaumei

Description. Based on adult male holotype , 3.0 mm. Body ( Figure 1 A), coxae 1–4 expanded distally, 2x as long as wide; with posterodistal tooth; coxa 4 with reduced posterior lobe; coxa 5 devoid of robust seta on ventromedial margin; coxae 6 and 7 quadrangular. Pleonites 1–3 untoothed; coxa 3 not reduced in size; epimera 1– 3 with 2, 4, 1 robust setae, respectively ( Figure 1 C). Head ( Figures 1 A, 1B). Lateral lobe mammilliform; anteroventral notch strong; eyes bigeminal, with 13 pairs of dispersed ommatidia (sensu McKinney & Barnard 1977 ). Antenna 1 ( Figure 1 B) geniculate; article one with a distoventral robust seta; article 2, 1.2x as long as 3; accessory flagellum 3–articulate, distal article vestigial; primary flagellum 13–articulate, as long as peduncle. Antenna 2 ( Figure 1 B), articles 4 and 5 subequal in length, flagellum 8–articulate, 1.6x as long as article 5 of peduncle. Mounthparts , lower lip ( Figure 2 A), lower corner on outer lobe upturned; inner lobe not well developed; with tuft of short setae on distal part of each lobes upper lip ( Figure 2 B) subtriangular, 1.2x longer than wide, ventrally covered with tiny setae. Maxilla 1 ( Figure 2 C), styliform; inner lobe with one distal robust seta and other 12 on inner margin; outer lobe narrow, 6 digital setae; palp 2–articulate subequal in length, article 2 with 4 robust and one simple setae, distally. Maxilliped ( Figure 2 D), inner lobe with 3 long and 4 short distal setae; devoid of setae on inner margin; 8 facial setae; bearing 4 long setae midway on outer margin; distal margin with 7 odontoid teeth and 5 pectinate long setae, 7 facial setae; palp 4–articulate, article 2 with a medial tuft of setae on inner margin; article 3 with a tuft of setae on distal inner margin; article 4 with bifid nail; articles 3–4 with stridulating ridges. Maxilla 2 ( Figure 3 A), outer lobe straight, 0.4x as wide as inner lobe, 10 long distal setae; inner lobe with 3 distal, 4 subdistal, 24 on inner margin, and 14 facial robust long setae. Mandibles ( Figures 3 B, 3C), molar well developed, triturative, bearing a long isolate seta; mandible palp 3–articulate; article 2, 1.3 x longer than 3, with one distal seta; article 3 with 7 short and 3 long D and 2 long curved E setae. Left mandible ( Figure 3 B) with 6 incisors, lacinia mobilis bifid, 10 rakers right mandible ( Figure 3 C), with 2 pairs of incisors separated; lacinia mobilis with 3 teeth and 7 rakers. Gnathopod 1 ( Figure 4 A), basis as long as carpus; with one long posterior seta backward; ischium with 2 posterodistal setae; merus with a posterodistally tuft of setae; carpus 2x as long as propodus; with long submarginal and marginal setae on posterior margin; palmar margin right; posterior corner of palmar margin defined by one robust seta; dactylus fixing palm. Gnathopod 2 ( Figures 4 B, C), basis as long as propodus; quadrate in section, bearing 2 distal concretions on each corner; ischium with 2 additional distal concretions on each corner; merus posterior lobe small, 3 setae; carpus 0.1x as long as propodus; palmar and posterior margin serrate; margin of propodus oblique, 4 distal robust setae, 2–3 short additional robust setae backward; dactylus stout, almost right, cylindrical. Pereopod 3 ( Figure 5 A), basis slender, as long as ischium, merus and carpus, combined; carpus 0.7x as long as propodus; dactylus with nail. Pereopod 4 ( Figure 5 B), basis slender, as long as ischium and merus, combined; carpus 0.8x as long as propodus; dactylus with one posterior seta and nail. Pereopod 5 ( Figure 5 C), basis as broad (measured proximally) as long, tapering distally, 0.8x as long as merus and carpus, combined, 12 robust short setae and one distal robust long seta, on anterior margin, 16 large posterior serrations; ischium with one anterodistal robust seta; merus with one seta midway on anterior and posterior margins, one robust and 2 small setae on anterior and one short and one large on posterior distal corners; carpus 2 robust setae midway on anterior margin, 3 robust setae in anterior and 5 in posterior corners; propodus 0.9x as long as carpus, 4 posterior setae distally; dactylus with one anterior setae and nail. Pereopod 6 , basis 0.8x as long as wide, proximally, and as long as carpus and propodus, combined, 9 robust setae on anterior, and 18 serrations on posterior margins; ischium with one anterodistal seta; merus 2 robust setae basally, 3 midway on anterior margin, 6 on anterodistall corner; one robust seta midway on posterior margin, and 2 on a small posterodistal lobe; carpus as long as merus, 3 robust setae midway on anterior margin, and 3 on anterodistal corner, 6 robust setae on posterodistal corner; propodus as long as merus and carpus, combined; 4 group of 2 robust setae on anterior margin, 4 in posterodistal corner; dactylus 2 anterior setae and nail. Pereopod 7 , basis 0.7x as broad as long, quadrangular; 8 robust setae in anterior and 27 serrations on posterior margins; ischium without setae; merus 4 robust setae on anterior margin, 3 setae on a small anterodistal lobe; 2 in posterior margin, and 2 in a small posterodistal lobe; carpus 3 robust setae on anterior and posterior distal corners; propodus 4 robust setae on posterodistal corner, 4 robust setae on anterior margin; dactylus with one anterior seta and nail. Urosomite 1–3 ( Figure 1 C), untoothed dorsally. Uropod 1 ( Figure 6 A), peduncle 0.8x as long as rami; one basal robust seta in outer margin; 3 small and 3 long robust setae dorsally; 2 robust–large setae distally; rami 2 dorsal and 4 robust setae, distally settled. Uropod 2 ( Figure 6 B), peduncle 1.2x as long as rami; one robust dorsal seta; rami 3–4 robust dorsal setae and 3–4 distally settled. Uropod 3 ( Figure 6 C), peduncle as long as outer ramus; 2 short and one long ventrodistal setae, 2 small dorsodistal setae; inner ramus like scale, 0.3x length of outer. Telson , 1.2x longer than broad, apices on each lobe deeply bifid, each with one short robust seta inserted into notch; 2 submarginal setae inserted dorsally midway from tip of each lobe. Epimeral plates ( Figure 1 A), plate 1 subquadrate, 2 robust setae on anterior half of ventral margin; epimeral plate 2 curved backward, 4 robust setae on anterior half of ventral margin; epimeral plate 3 convex backward to form a posteroventral tooth; one anterior large robust seta. Paratype , female similar than male, but gnathopod 2 ( Figure 6 D) long and slender; basis as long as carpus and propodus, combined; basis 2 short setae on anterior margin; 4 setae on posterior margin; ischium 2 posterodistal setae; merus reduced in length, posterior margin obtuse, one long seta; carpus triangular, one dorsal seta distally; 5 tuft of curved forward setae, in posterior margin; propodus 5 equidistant setae on anterior margin; palm oblique; 2 long and 2 short setae on palmar margin; 2 long setae backward, surpassing anterior half of carpus; gill as long as basis and ischium, combined; oostegite poorly developed.