Protohyale arabica, Myers, Alan A. & Nithyanandan, Manickam, 2016

Myers, Alan A. & Nithyanandan, Manickam, 2016, The Amphipoda of Sea City, Kuwait. — The Senticaudata (Crustacea), Zootaxa 4072 (4), pp. 401-429 : 402-405

Family Hyalidae Bulycheva, 1957

Protohyale arabica sp. nov. ( Figs 1–3 )

Type material. Male holotype, 5.0 mm ( NHMUK 2015. 3058), Station A2, Sea City, Kuwait, seaweeds and associates, 23 March 2010, M. Nithyanandan. Paratypes 32 males, 31 females ( NHMUK 2015. 3059–3068), same data as holotype.

Other material. 1 male, 2 females ( NHMUK 2015. 3069–3071), Sea City, Kuwait, soft benthos, 24 October 2012, M. Nithyanandan.

Etymology. Named after the region of the type locality.

Description. Based on male holotype, 5.0 mm.

Head. Head lobes truncate; eye round. Antenna 1 scarcely half-length of antenna 2; peduncular article 2 subequal with peduncular article 3. Antenna 2 less than half body length. Labium inner plates vestigial. Maxilla 1 inner plate with two stout distal setae; palp extending beyond bases of setae on outer plate. Maxilla 2 without oblique setal row. Mandible lacking palp; lacinia mobilis 5-dentate. Maxilliped palp long; fourth article extending well beyond tip of outer plate; article 7 very long and whip-like.

Pereon. Gnathopod 1 coxa large without posteroproximal shelf, posterior face with two very stout setae; basis expanded with moderately well developed anterodistal lobe; propodus elongate, longer than carpus, subrectangular; dactylus short, broad. Gnathopod 2 coxa large, subround with weak posteroproximal shelf; basis enlarged with strong anterodistal lobe; carpus very small, triangular; propodus greatly enlarged, subovoid, palm relatively short, only moderately oblique, defined by a strong, subacute spine; dactylus fitting palm. Pereopod 3 basis parallel-sided. Pereopod 5 basis subround with small mid posterior margin notch, crenulate on posterodistal part; dactylus well developed with small seta on posterodistal margin. Pereopod 6 basis subrectangular with small mid posterior margin notch, crenulate on posterodistal part; dactylus well developed with small seta on posterodistal margin. Pereopod 7 basis very expanded, subround, crenulate on posterior margin; dactylus well developed with small seta on posterodistal margin.

Pleon. Epimeron 1 rounded. Epimeron 2 subrectangular. Epimeron 3 weakly extended on posterior distal margin into a triangular spine. Uropod 1 peduncle with strong distolateral robust seta; rami a little longer than peduncle, subequal in length. Uropod 2 peduncle short; inner ramus much longer than peduncle and longer than outer ramus. Uropod 3 peduncle more than twice length of single ramus. Telson unarmed.

Female (sexually dimorphic characters). Gnathopod 2 basis expanded distally; carpus moderately large, subrectangular; propodus elongate, subrectangular, palm short, oblique; dactylus fitting palm.

Remarks. This species is similar to P. corallinicola ( Hirayama, 1980) , and to P. schmidti ( Heller, 1866) . It differs from both species, however, in the form of the male gnathopod 2. In P. a r ab i ca sp. nov., the palm is only moderately oblique reaching about one third the length of the posterior margin of the propodus, and is defined by a subacute spine. In P. corallinicola and in P. schmidti , the palm is very oblique, reaching at least half of the posterior margin of the propodus and is defined by an ill-defined rounded hump. It also differs from P. schmidti in the form of the maxilliped palp which is stout in P. schmidti but slender in P. arabica sp. nov.

Distribution. Kuwait.

Figures

FIGURE 1. Protohyale arabica sp. nov. male, 5.0 mm, Sea City, Kuwait.

FIGURE 2. Protohyale arabica sp. nov. male, 5.0 mm, Sea City, Kuwait.

FIGURE 3. Protohyale arabica sp. nov. male, 5.0 mm, female 5.0 mm, Sea City, Kuwait.