Victoriopisa cusatensis, Joseph & Nandan & Jayachandran, 2018

Joseph, Philomina, Nandan, S. Bijoy & Jayachandran, P. R., 2018, New species of Victoriopisa Karaman & Barnard, 1979 (Crustacea: Amphipoda: Eriopisidae) from Vembanad backwaters, Southwest coast of India, Zootaxa 4433 (1), pp. 59-70 : 63-68

Victoriopisa cusatensis sp. nov.

( Figs. 2–8 )

Material examined. Holotype: male (ZSI C7391/2), 8.6 mm, mangrove area of Valanthakad Island in Vembanad backwater, Kochi, Kerala, 9°55’10.24” N and 76°20’ 01.23” E, 18 February 2012, coll. Philomina Joseph. Paratypes: 1 male (MBBM-SBN-H-6383), 8.4 mm ; 2 females (ZSI C7392/2), 7.6 mm, (MBBM-SBN-H-6384), 6.7mm same locality as holotype, 26 February 2017, coll. Philomina Joseph.

Diagnosis. Body slender, laterally compressed. Head with eyes and lateral cephalic lobe. Antenna 1 large with expanded peduncle article 1, larger than head; peduncle article 2 seems to be projected dorsolaterally; accessory flagellum 2-articulate, not reaching the first flagellar article. Gnathopod 2 palm smooth. Epimeral plates with posteroventral tooth. Pereopod 7 basis and merus largely expanded. Pleopods with more than 20 articles in outer rami. Urosomites separate; Uropod 3, outer rami 2-articulate, inner rami scale like. Telson with one subapical spine and two lateral spines on each lobe.

Etymology. The species name ‘ cusatensis ’ refers to the Cochin University of Science and Technology (CUSAT), a premium institution in India considering its contribution in the field of Marine Sciences.

Description. Based on holotype male, 8.6mm, ZSI C7391/2.

Head. Eyes small, rounded; lateral cephalic lobe large and triangular, anteroventral sinus indistinct. Antenna 1 half times body length; peduncular articles length ratio from 1-3 is 1.0:0.6:0.2; peduncular article 1 well developed, without setae along posterior margin, 14 transverse ridges in posteroproximal angle; peduncular article 2 geniculate, dorsolateral margin seems to be projected; primary flagellum with 33 articles on right and 30 articles on left with distal setae, aesthetasc begins from article 8; accessory flagellum with 2 articles shorter than article 1 of primary flagellum. Antenna 2 shorter, about a third length of antenna 1; peduncular article 2 cone gland not reaching the end of peduncular article 3, peduncular article 4 and 5 subequal (1.8:1.7); flagellum highly setose, with two fused long articles and three short articles. Upper lip wider than deep and semicircular with row of fine setae. Lower lip inner lobes well-developed; outer lobes with apical setae. Mandible palp 3-articulate with length ratio 1:3.7:3.1, article 3 shorter than article 2; left incisors with 6 teeth and right with 5 teeth; lacinia mobilis with 4 teeth on both side; accessory setal row with 10 serrated setae; molar large and triturative. Maxilla 1 inner plate rectangular, with 6 plumose setae on left maxilla and 5 on right; outer plate with 9 serrated apical spines; palp 2- articulate, left palp article 2 with 2 stout spines, 4–5 robust setae and 5 simple setae on apical margin, right palp with 8 robust setae and 5 simple setae. Maxilla 2 inner plate armed with 7 plumose setae in oblique row and simple setae on apical margin. Maxilliped inner plate with 3 stout apical spines on right maxilliped and 4 on left, 6 robust setae on apical margin and few sub apical plumose setae; outer plate with 6 robust setae and many simple setae on apical and lateral margin; palp 4-articulate, article 2 long, highly setose on lateral margin, article 3 with many long apical setae and three subapical setae, article 4 claw-like with few setae at the dorsoventral margin.

Pereon. Gnathopod 1 coxa anteroventrally produced; basis with 4 setae on posterior margin and 4–5 setae on posterodistal corner; merus with 6–8 simple setae distally; carpus ovoid, highly setose along the posteroventral margin, larger than propodus; propodus palm transverse and broad distally, palm with 4 short spines on posterodistal corner accompanied by 5 simple setae, 10–12 sparse setae along the entire margin; dactylus smooth, curved with 7 sparse setae on inner margin and one simple setae on outer margin. Gnathopod 2 coxa ovoid, convex anteroventrally; basis with 6 long setae along posterior and distal margins respectively; carpus with transverse row of marginal setae; propodus broad, palm smooth with 3 stout spines, 10–12 sparse setae in palmar margin; dactylus closing along palm, inner margin smooth, armed with 14 sparse setae, outer margin with 1 medial seta. Pereopod 3 coxa broad, ovoid; basis with 10 long setae at the posterior margin, fine setae on anterior margin, 5 setae distally; merus slightly enlarged distally; carpus ovoid, subequal to propodus; propodus setose marginally, a robust setae on posterodistal corner; dactylus curved, with a medial setae. Pereopod 4 coxa rectangular; basis linear with 8 long setae at posterior margin, fine setae at anterior margin; merus, carpus, propodus and dactylus similar to pereopod 3. Pereopod 5 short, stout; coxa partially lobate; basis oblong; merus with 2 anterior robust setae and few posterior simple setae; carpus setose, armed with 8–9 robust setae; propodus with 5 robust setae; dactylus simple armed with 2 simple setae at posteroproximal margin and 2 sub-distal setae. Pereopod 6 coxa shallow; basis oblong, with minute castellation; merus and carpus with similar setal armature as that of pereopod 5; propodus with 8 robust setae, 3 at posterior margin, 2 posterodistally and 3 anterodistally. Pereopod 7 coxa small, rectangular; basis broadly expanded, castelloserrate, basilar width ratio of pereopod 5, 6, 7 follows the order 1:1.4:2.4 respectively; merus broadly expanded, anterior margin with 5 robust setae, posterior margin with 3–4 groups of long setae; carpus with 4 robust setae accompanied by simple setae; propodus with 6 robust setae, 4 at posterior margin and 2 distally.

Pleon. Epimera 1–3 with small acute tooth at posteroventral corner, epimera 2 with a row of 8 plumose setae, epimera 3 with 3 small acute spine ventrally. Pleopods peduncle nearly quadrate, with paired retinacula on inner margins and plumose setae on outer margins. Pleopod 1 peduncle with 8 plumose setae, outer rami with 26 articles and inner rami with 18 articles; pleopod 2 peduncle with 6 plumose setae, outer rami with 23 articles and inner rami with 17 articles; pleopod 3 peduncle without plumose setae, outer rami with 23 articles and inner rami with 17 articles. Urosomites not fused, uropod 1 peduncle with 2 robust setae and a spine distally, outer rami subequal to inner rami, outer rami with 3 robust setae in inner margin and 5 robust setae distally; inner rami with 2 robust setae in the inner margin and 5 robust setae distally. Uropod 2 peduncle with 3 robust setae; outer rami smaller, outer and inner rami with 3 robust setae in the inner margin and 5 robust setae distally. Uropod 3 parviramous, inner rami scale like, 0.15 times that of proximal article of outer rami; outer rami much enlarged with 2 articles, longer and broader proximal article and smaller distal article, proximal article with three robust setae on outer margin, 2–3 robust setae and simple setae distally, distal article with fine setae, three on inner and two on outer margins and tuft of long setae apically. Telson deeply cleft, each lobe with one subapical long robust setae and two marginal small robust setae, right apex is tooth like and left apex smooth with simple setae.

Description of female (Paratype, 7.6 mm, ZSI C7392/2). Antenna 1: peduncle article 1 is dilated as in male specimens; article 2, dorso-lateral margin without projection, right flagellum with 20 articles, left flagellum with 18 articles.

Maxilla 1: inner plate of first maxilla bears 5 plumose setae on right and left side, palp is similar in both.

Oostegites: long ovoid with simple setae along the margins, present in gnathopod 2 and in pereopods 3, 4 and 5, absent in male.

Gnathopod 2: similar in both sexes, with smooth palmar margin.

Pleopods: peduncle with paired retinacula in inner margin, pleopod 1 peduncle with 8 plumose setae in outer margin, pleopod 2 with 4 plumose setae and pleopod 3 with 1 plumose setae; pleopods 1–3 bears 18 articles in outer rami and 13 articles in inner rami.

Telson: with only two robust setae on either half, one subapically and one laterally.

Remarks. Victoriopisa cusatensis sp. nov differs from the other Indian species: V. chilkensis and V. papiae in having following characters (features of V. chilkensis and V. papiae in parentheses): (1) smooth palm of gnathopod 2 (1 excavation and 1 prominence in V.chilkensis and 3 prominences in V. papiae ); (2) smooth dactylus (a prominence in V. chilkensis and V. papiae ); (3) peduncular article 2 of antenna 1 projected dorsolaterally (smooth in V. chilkensis and V. papiae ); (4) inner plate of maxilliped with 3 spine on right and 4 on left (3 in V. chilkensis and V. papiae ); (5) epimeral plate 2 with 8 plumose setae (9 setae in V. chilkensis , 10 in V. papiae ); (6) inner plate of maxilla 1 rectangular with 5 plumose setae on right and 6 on left (triangular with 10 setae in V. chilkensis , rectangular with 7 setae in V. papiae ); (7) telson with 1 apical and 2 lateral spines (1 apical spine and no lateral spines in V. chilkensis ,1 subapical spine and 2 apical spine in V. papiae ). Three Indian species were similar in presence of eyes, broader basis and merus of peropod 7, smaller gnathopod 1 compared to gnathopod 2.

Victoriopisa cusatensis sp. nov. differ from other Asian species in having smooth palm and dactylus of gnathopod 2; while V. wadai and V. multiartus is present excavated palm and smooth dactylus; whereas V. ryukyuensis and V. bruneiensis have prominences in the palm and excavation on dactylus, V. tinggiensis and V. bantenensis presents smooth palm and dactylus as the new species, but differs from it by having a deep cephalic notch, V. cusatensis sp.nov. also differs from V. atlantica , V. australiensis , V. guanarocana , V. epistomata , V. marina , by the presence of eyes.

Habitat. Brackish, mangrove fringed area, depth 1–2 m, silty sand, salinity 17.9 PSU, organic matter-4.17 %

Figures

FIGURE 2. Victoriopisa cusatensis sp. nov., holotype, male habitus (8.6 mm), ZSI C7391/2, mangrove sediment, Valanthakad Island, Vembanad backwater, Kochi, Kerala, scales: habitus male (♂), 1 mm; A1, A2, H, 0.5 mm.

FIGURE 3. Victoriopisa cusatensis sp. nov., holotype, male habitus (8.6 mm), ZSI C7391/2, mangrove sediment, Valanthakad Island, Vembanad backwater, Kochi, Kerala, scales: MP, LL, 0.3mm; MX1, MX2, MD, 0.2mm; UL, 0.1mm.

FIGURE 4. Victoriopisa cusatensis sp.nov., holotype, male habitus (8.6 mm), ZSI C7391/2, mangrove sediment, Valanthakad Island, Vembanad backwater, Kochi, Kerala, all scales:0.5 mm

FIGURE 5. Victoriopisa cusatensis sp. nov., holotype, male habitus (8.6 mm), ZSI C7391/2, mangrove sediment, Valanthakad Island, Vembanad backwater, Kochi, Kerala, all scales:0.5 mm.

FIGURE 6. Victoriopisa cusatensis sp. nov., holotype, male habitus (8.6 mm), ZSI C7391/2, mangrove sediment, Valanthakad Island, Vembanad backwater, Kochi, Kerala, scales: PL1,PL2,PL3,U1,U2, 0.5mm; T, 0.1mm.

FIGURE 7. Victoriopisa cusatensis sp. nov., SEM images,male habitus (8.4 mm), MBBM-SBN-H-6383, mangrove sediment, Valanthakad Island, Vembanad backwater, Kochi, Kerala, scales:habitus male (♂), 1mm; A1, 500µm; AF, 20µm; G2, 200µm.

FIGURE 8. Victoriopisa cusatensis sp. nov., SEM images, male habitus (8.4 mm), MBBM-SBN-H-6383, female habitus,♀ (6.7mm) MBBM-SBN-H-6384, mangrove sediment,Valanthakad Island, Vembanad backwater, Kochi, Kerala, scales: habitus female (♀), 1 mm; EP, U3, 500µm; MX1 PA, MD, 20 µm; MX1 O, 10 µm.