Parhyale piloi, Myers & Trivedi & Gosavi & Vachhrajani, 2017

Myers, Alan A., Trivedi, Jigneshkumar N., Gosavi, Swapnil & Vachhrajani, Kauresh D., 2017, A new species of genus Parhyale Stebbing, 1897 (Crustacea, Amphipoda, Hyalidae) from Gujarat State, India, Zootaxa 4294 (5), pp. 593-599 : 594-595

Parhyale piloi sp. nov.

( Figures 1–4 )

Type material. Holotype male, 12.0 mm, ( ZSI, WRC-C.1601), Shivrajpur village (22°19'58''N 68°57'01''E), underneath rock surface, 22 March 2017, Coll. Jignesh Trivedi and Swapnil Gosavi . Allotype female, 9.5 mm, ( ZSI, WRC-C.1602) same data as holotype . Paratypes 3 males, 10.9 mm; 12.2 mm: 11.1 mm; 3 females, 6.1 mm; 7.6 mm; 9.3 mm, ( ZSI, WRC-C 1603 ), same data as holotype .

Other material. 18 males, 9.1 mm – 10.5 mm; 12 females 6.1 mm – 7.9 mm, (ZL-AR-AM-1), Shivrajpur village (22°19’58”N 68°57’01E), underneath rock surface, 8 February 2017, Coll. Dhruva Trivedi and Kauresh Vachhrajani.

Type locality. Shivrajpur village (22°19'58''N 68°57'01''E), coral reef, intertidal, Saurashtra coast, Gujarat state, India

Etymology. The species is dedicated to Professor Bony Pilo, former head of Department of Zoology, The Maharaja Sayajirao University of Baroda, Vadodara, for his valuable contribution to biodiversity studies of Gujarat state.

Description. Based on male holotype, 12.0 mm.

Head. Head with lateral cephalic lobes quadrate; eye round, of medium size. Antenna 1 short about half length of antenna 2; article 1 a little longer than article 2; article 2 scarcely longer than article 3; flagellum less than twice length of peduncle with 14 articles. Antenna 2 twice length of antenna 1; peduncular article 5 longer than 4; flagellum more than twice length of peduncle with 23 articles. Labrum rounded, distally setose. Labium mandibular processes short, rounded. Mandible molar strong; left lacinia mobilis 5–dentate. Maxilla 1 inner plate narrow with two terminal robust setae; palp extending beyond distal margin of outer plate, consisting of one article, constricted near its distal end. Maxilla 2 without oblique setal row. Maxilliped palp robust; article 2 as broad as long; article 3 distally setose; dactylus strong, falcate.

Pereon. Gnathopod 1 coxa with well-developed shelf on posterior margin; basis broadening medially; carpus and propodus subequal in length; propodus posterior margin and palm continuously convex, but palm delimited by two robust setae; dactylus short and stout, not swollen medially. Gnathopod 2 coxa deeper than broad with well developed shelf on posterior margin; basis broadening distally without strong anterodistal lobe, but with small anterodistal subacute spine; carpus small, cupshaped; propodus very large, posterior margin forming distinct angle with straight palm, palm delimited by two strong robust setae, palm with many smaller robust setae; dactylus fitting palm. Pereopods 3–4 similar; dactylus about one third length of propodus, with fine seta on posterior margin. Pereopods 5–7 increasing in length posteriorly. Pereopod 5 basis much broader than long, with very large flange on posterior margin. Pereopod 6 basis longer than broad; propodus with setae on both anterior and posterior margins. Pereopod 7 basis scarcely longer than broad, the posterior margin scalloped; propodus with setae on both anterior and posterior margins.

Pleon. Epimera 2–3 rounded. Uropod 1 peduncle subequal in length with subequal rami, with strong distolateral robust setae. Uropod 2 peduncle a little longer than rami. Uropod 3 biramous; outer ramus subequal with peduncle, with 5 distal setae; inner ramus minute with a single distal seta. Telson completely cleft, each half subtriangular, lacking setae.

Female (sexually dimorphic characters). Gnathopod 1 basis broadening distally, anterodistal margin with right-angled spine; carpus subequal in length with propodus, posterior margin a rounded lobe; propodus subrectangular, posterior margin sinuous, palm almost straight, weakly oblique; dactylus fitting palm. Gnathopod 2 similar to gnathopod 1; propodus broader, palm more oblique.

Habitat. Underneath rocks on coral platform.

Distribution. Known only from the type locality.

Remarks. Parhyale piloi sp. nov. is closely related to P. darvishi Momtazi & Maghsoudlou (2016) from the Persian Gulf and Gulf of Oman, but differs in a number of significant ways. In P. darvishi , the male gnathopod 1 propodus has a distinct angle between the posterior margin and the palm, whereas in Parhyale piloi sp. nov., the palm and posterior margin are evenly convex. In the male gnathopod 2 of P. darvishi , the propodus posterior margin and palm are continuously and evenly rounded, however in Parhyale piloi sp. nov., the propodus and palm are clearly delimited from one another, the posterior margin forming distinct angle with straight palm and the dactyl is shorter and stouter. In the female of Parhyale piloi sp. nov., the gnathopod 1 propodus posterior margin is sinuous but is straight in P. darvishi . In Parhyale piloi sp. nov., the maxilla 1 palp extends beyond the distal margin of the outer plate, whereas in P. darvishi it is shorter than the outer plate. In Parhyale piloi sp. nov., the labium has very short rounded mandibular processes but in P. darvishi the mandibular processes are relatively long and subacute. In Parhyale piloi sp. nov., pereopods 6 and 7 have setae on both anterior and posterior margins of the propodus, whereas in P. darvishi , the propodus is naked on the anterior margin. In Parhyale piloi sp. nov., epimeron 3 is rounded but in P. darvishi they are semiquadrate. Parhyale piloi sp. nov., also differs from P. darvishi in the outer ramus of uropod 2 having marginal robust setae, whereas these are absent in P. darvishi .

Parhyale piloi sp. nov., is also similar to P. fascigera Stebbing, 1897 from the West Indies, and west Pacific and according to Momtazi & Maghsoudlou (2016) also from the east Atlantic. That species, however, is more similar to P. darvishi in having a male gnathopod 1 propodus with a distinct angle between the posterior margin and the palm; a female gnathopod 1 with a straight posterior margin to the propodus; a maxilla 1 palp shorter than the outer plate; a labium with strong subacute mandibular processes; pereopods 6–7 with naked anterior margins to the propodus and epimeron 3 posterodistal margin with a distinct spine.

Figures

FIGURE 1. Parhyale piloi sp. nov., male holotype, 12.0 mm, ZSI, WRC-C. 1601, Shivrajpur village (22 ° 19 ' 58 '' N 68 ° 57 ' 01 '' E), Gujarat State, India. Habitus, fresh coloration

FIGURE 2. Parhyale piloi sp. nov., male paratype, 12.3 mm, ZSI, WRC-C. 1603, Shivrajpur village, Gujarat State, India.

FIGURE 3. Parhyale piloi sp. nov., male paratype, 12.3 mm, ZSI, WRC-C. 1603; female paratype, 9.3 mm, ZSI, WRC- C. 1603, Shivrajpur village, Gujarat State, India.

FIGURE 4. Parhyale piloi sp. nov., male paratype, 12.3 mm, ZSI, WRC-C. 1603, Shivrajpur village, Gujarat State, India.