Cymadusa priscileo, Hughes, Lauren E. & Peart, Rachael A., 2013

Hughes, Lauren E. & Peart, Rachael A., 2013, New species and new records of Ampithoidae (Peracarida: Amphipoda) from Australian Waters, Zootaxa 3719 (1), pp. 1-102 : 64-66

Cymadusa priscileo sp. nov.

( Figs. 38 , 39 )

Type material. Holotype male, 10.5 mm, dissected, 4 slides, AM P.77458, south of Broulee Island, New South Wales, Australia (35°50’50”S 150°11’05”E), 8 m, from macroalga Halopteris platycena , 25 October 2002, coll. A. Millar and N. Yee (NSW 1990).

Additional material examined. Western Australia: 1 male, AM P.88407, Success Bank (35°5’S 114°51’E), depth unknown, in seagrass Amphibolis sp., August/ September 2009, coll. Pauline Vouriot; 1 specimen, AM P.88408, Rottnest Island (32°00’48”S 115°27’30”E), depth unknown, in seagrass Amphibolis sp., August/ September 2009, coll. Pauline Vouriot.

Etymology. Priscileo , a native Australian marsupial cat, in reference to the feline nail-like dactylus of gnathopod 2; used as a noun in apposition.

Diagnosis. Antenna 1 peduncle article 1 posterior margin with clusters of robust setae; accessory flagellum 2- articulate. Mandible accessory setal row with 7 robust setae. Maxilla 1 inner plate with 7 slender setae; outer plate palp broad, with 8 robust setae. Gnathopod 1 coxa distinctly larger than coxa 2, anterior margin concave, anteroventral corner rounded; basis subequal in length to coxa, anterodistal corner subquadrate, with 1 robust seta; carpus anterior margin with 3 short robust setae; propodus subovoid to subrectangular, length twice width, palm acute, convex, defined by 1 robust seta, without corner or tooth, palm length 0.5 times posterior margin. Gnathopod 2 basis longer than coxa, anterodistal lobes large, rounded, not reaching beyond ischium, with 1 robust setae; ischium anterior margin bilobate; carpus compressed, cup-shaped, length subequal to width, 0.3 times propodus length, anterior margin with 10 robust setae; propodus subtriangular, palm subacute, sculptured, distal palmar tooth subtriangular with 2 subacute midmedial teeth, palm defined by subacute tooth and subquadrate corner, without palm defining robust setae, palm length 0.6 times posterior margin; dactylus claw-like, much shorter than palm, apically blunt, unguis minute. Telson apically rounded, 1 pair of lateral setae, and 1 pair of apical setae.

Description of holotype. Head. Antenna 1 article 1 length 1.5 times article 2, posterior margin with clusters of robust setae; article 2 length 2.1 times article 3; article 3 length 0.25 times article 1; primary flagellum with 21 articles; accessory flagellum 2-articulate. Antenna 2 unknown. Mandible accessory setal row with 7 robust setae; palp 3-articulate, slender; article 2 with 2 slender setae; article 3 length 4 times width. Lower lip outer plates without notched or slit, with single pair of apical ducts; mandibular lobes with curved margins, subacute apically. Maxilla 1 inner plate with 7 slender setae; outer palp broad, with 8 robust setae.

Pereon. Coxae 1–4 longer than broad. Gnathopod 1 smaller than gnathopod 2; coxa 1 distinctly larger than coxa 2, anterior margin concave, anteroventral corner rounded; basis subequal in length to coxa, anterodistal corner subquadrate, with 1 robust seta; ischium anterior margin without lobe; merus posterodistal corners acutely produced; carpus subtriangular, length twice breadth, subequal to propodus length, anterior margin with 3 short robust setae; propodus subovoid to subrectangular, length twice width, palm acute, convex, defined by 1 robust seta, without corner or tooth, palm length 0.5 times posterior margin; dactylus overreaching palm, apically acute, tapering evenly, inner margin crenate. Gnathopod 2 sexually dimorphic; basis longer than coxa, anterodistal lobes large, rounded, not reaching beyond ischium, with 1 robust setae; ischium anterior margin bilobate; merus posterodistal corner truncate; carpus compressed, cup-shaped, length subequal to width, 0.3 times propodus length, anterior margin with 10 robust setae; propodus subtriangular, length 1.6 times width, palm subacute, sculptured, distal palmar tooth subtriangular, with 2 subacute midmedial teeth, palm defined by subacute tooth and subquadrate corner, without palm defining robust setae, palm length 0.6 times posterior margin; dactylus claw-like, much shorter than palm, apically blunt, unguis minute, inner margin crenate.

Pleon. Epimeron 1 broadly rounded, posterior margin rounded, posterodistal corner rounded. Epimera 2–3 subquadrate, posterior margin straight, posterodistal corner subquadrate. Uropod 1 long, reaching past uropod 2 rami; peduncle length 3 times width, with 8 robust setae, with large, acute distoventral spine; inner ramus 0.9 times peduncle length, longer than outer ramus, with 3 marginal robust setae; outer ramus slender, length 5 times width, with 4 marginal robust setae. Uropod 2 peduncle with 3 robust setae, without distoventral spine; inner ramus longer than outer ramus with 4 marginal robust setae; outer ramus with 2 marginal robust setae. Uropod 3 peduncle length twice width, 2.3 times rami length, with 3 distal slender setae, with 4 marginal and 4 distal robust setae; inner ramus length twice width, 0.45 times length of peduncle, with 3 distal robust setae, 2 distal slender setae and 2 lateral robust setae; outer ramus shorter than inner ramus with 1 lateral robust seta. Telson subtrapezoidal, apically rounded, with small apical cusps, 1 pair of lateral setae, 2 pair of lateral plumose setae and 1 pair of apical setae.

Remarks. Cymadusa priscileo sp. nov. is characterised by the short male gnathopod 2 dactylus, which is shorter than half the palm length. This character aligns C. priscileo sp. nov. with C. brevidactyla , C. cavimana and C. smilodonta . Cymadusa priscileo sp. nov. differs from the latter species in the male gnathopod 2 propodus palm which has a more sculptured margin and the palm defined by a subacute tooth. The gnathopod 2 carpus anterior margin with rows of short robust setae also distinguishes Cymadusa priscileo sp. nov. from all other Cymadusa .

Distribution. New South Wales: Broulee Island (current study). Western Australia: Success Bank; Rottnest Island (current study).

Figures

FIGURE 38. Cymadusa priscileo sp. nov., holotype male, 10.4 mm, AM P. 77458, Broulee Island, New South Wales.

FIGURE 39. Cymadusa priscileo sp. nov., holotype male, 10.4 mm, AM P. 77458, Broulee Island, New South Wales, scales 0.1 mm.