Description

Description (based on the holotype ♂, ZRC 2018.0493) BODY. Subcylindrical. HEAD. Eyes present and well developed, set just posterior to margin of lateral lobe. Epimeral plate 3 about 1.4 times as long as 1 or 2. Head as deep as long, longer than pereonite 1; anteroventral margin moderately excavate, corner sharp. ANTENNA 1 (Fig. 3 A 1). Peduncular articles 1 – 3 with ratio of 4: 5: 2; article 1 margins slightly convex with clump of slender setae near ventrodistal corner; article 2 slender, dorsal and ventral margins lined with slender setae; article 3 short, accessory flagellum present, uniarticulate, apically acute, half the length of flagellar article 1 with long slender apical setae; flagellum with at least 11 articles, distal margin of each article possessing short slender setae. ANTENNA 2 (Fig. 3 A 2). Shorter and more robust than 1; peduncular articles combined length twice as long as flagellum; peduncular articles 3 – 5 with length in ratio 2: 5: 5; peduncular article 1 subquadrate, ventrodistal corner with long slender and 1 robust setae; article 2 ventral margin with short to long slender setae; article 3 slender, margins with slender setae; flagellum with 8 articles, distal margin of each fringed with slender setae, articles 6 – 8 with robust setae on ventrodistal margin, article 8 distally tapering. UPPER LIP (Fig. 4 UL). Broader than long, margin covered in short fine setae, distal margin prepubescent. LOWER LIP (Fig. 4 LL). Outer lobe entire margin covered in fine setae, medial margins prepubescent, distomedial corner with arborescent setae, distal margin possessing one plumose apical setae; mandibular lobe blunt, distally possessing short setae. MANDIBLES (Fig. 4 MD). Well developed, subtriangular; incisors each with 4 teeth; lacinia mobilis on left mandible with 4 teeth, right mandible with 2 teeth; spinal row armed with 6 processes; molar process well developed, rounded; palp triarticulate, article 1 shortest with article 3 longest; article 2 laterodistal margin slightly expanded, article 3 linguiform, apically rounded, lateral margin with long slender setae, left mandible apical and comb setae plumose, right mandible apical setae plumose, comb setae slender. MAXILLA 1 (Fig. 4 MX 1). Inner lobe vestigial; outer lobe distally truncate with 8 apical denticulate setae, proximolateral margin with fine setae; palp biarticulate; article 1 0.3 times as long as article 2; article 2 linguiform, distally rounded with 6 apical robust setae and 4 subapical setae, distolateral margin with 3 slender setae. MAXILLA 2 (Fig. 4 MX 2). Inner lobe subequal in length to outer lobe; inner lobe medial and lateral margins slightly convex, deep face covered in short setae, medial margin possessing long plumose setae; outer lobe lateral and medial margins straight, slightly distally expanded, lateral margin with short setae, distal end rounded with mixture of long slender and plumose setae. MAXILLIPED (Fig. 4 MXP). Inner lobe distally truncate, extending slightly beyond article 1 of palp, lateral margin with fine setae, medioproximal margin with long robust setae, mediodistal margin with 8 – 10 slender setae and 4 apically oblique processes; outer lobe almost reaching end of article 2 of palp, apically rounded with long robust setae, lateral margin convex and with fine setae, medial margin straight with robust setae and submarginal slender setae; palp 4 - articulate, article 2 medial margin with long slender setae, article 3 distal margin covered in long slender setae with 1 – 2 serrate setae, article 4 subtriangular ending in a stout spine. GNATHOPOD 1 (Fig. 3 G 1). Enlarged, more robust than 2, carpochelate; coxa small, anterodistally unproduced; basis posteriorly expanded, ventrodistal corner with slender setae; ischium subquadrate, ventrodistal corner with slender setae; merus not anterodistally produced, sparsely setaceous along distal margin; carpus enlarged, twice as long as propodus; dorsal margin convex, ventral margin straight, entire margin with slender setae, proximoventral corner with apically acute process, inner midface possessing apically acute process, anteroventral corner with 2 processes forming a broad excavate sinus; propodus posterodistal margin slightly expanded, fringed with slender setae; dactylus less than half length of propodus with notch ¾ of the way up ventral margin. GNATHOPOD 2 (Fig. 3 G 2). Smaller than 1, subchelate; coxa subquadrate; basis distally expanded, anterodistal margin without flange, anterior margin crenulate; ischium subquadrate; merus with long setae on distal margin; carpus obovate, longer than propodus, dorsal margin moderately setose with long slender setae midway up margin, ventral margin with slender setae mid-margin; propodus dorsal and ventral margins parallel, dorsal margin with long slender setae, ventral margin with shorter slender setae, palm serrulate with a row of sub-marginal robust setae; dactylus curved, half the length of propodus, ventral margin doubly serrate. PEREOPOD 3 – 4 (Fig. 5 P 3 – P 4). Coxae subquadrate; basis slightly expanded; ischium subquadrate; merus distally expanded, dorsodistal margin with a pair of long robust setae, dorsal and ventral margins sparsely setaceous; carpus subovate; propodus elongate, longer than carpus, dorsal and ventral margins sparsely setaceous; dactylus falcate. PEREOPOD 5 (Fig. 5 P 5). Shortest; coxa posteriorly expanded into a tapering apically blunt process; basis with robust setae along anterior margin; ischium subquadrate; merus anterior margin with slender setae, anterodistal corner with a pair of long robust setae, posterodistal corner with 1 robust setae; carpus anterior margin with 3 robust setae, posterior margin with 3 short robust setae; propodus slender, with 4 short to long robust setae along anterior margin and 4 short robust setae along posterior margin; dactylus falcate. PEREOPOD 6 – 7 (Fig. 5 P 6 – P 7). Pereopod 6 shorter than 7; coxa small, anterodistally expanded into a tapering apically blunt process; basis posterior margin with plumose setae, anterior margin possessing short robust setae; ischium subquadrate; merus slightly expanded posterodistally, posterior margin with 3 long slender setae, anterior margin with short setae; carpus slender, anterior margin with short slender setae, posterior margin with 1 – 4 robust setae, posterodistal corner with long robust setae; propodus slender, ventrodistal corner possessing long slender setae; dactylus falcate. UROPOD 1 (Fig. 6 U 1). Biramous, peduncle longer than rami, inner and outer rami subequal in length; peduncle lateral margin with 5 robust setae, medial margin with 4 robust setae, interramal spine present and shorter than peduncle; outer ramus with 3 robust setae on outer margin, apice with 4 robust setae. UROPOD 2 (Fig. 6 U 2). Biramous, peduncle subequal in length to inner ramus, outer ramus longer than inner ramus; peduncle lateral and medial margins with 2 robust setae; outer ramus lateral margin with 3 robust setae, medial margin with 2 robust setae, apice with 5 robust setae; inner ramus with 4 apical setae. UROPOD 3 (Fig. 6 U 3). Uniramous, ramus 3 times longer than peduncle; peduncle broader than long, outer lobe covered in short fine setae; ramus long, medial margin with 3 long serrate setae, lateral margin with 2 long serrate setae, distal end with 1 long apical setae and 3 long subapical serrate setae. TELSON (Fig. 6 T). Rhomboidal, broader than long, apically truncate, superior face with 4 short setae, distal margin with short fine setae, distolateral margins with long robust setae. Female (dimorphic characters; based on the paratype ♀, ZRC 2018.0494) GNATHOPOD 1 (Fig. 7 G 1). Subchelate, smaller than male; merus distal margin with one serrate setae; carpus ventrally expanded, with row of serrate setae on ventral margin; propodus subequal in length to carpus, obovate, palm serrate; dactylus about 0.75 times as long as propodus, palm serrate, defined by strong posterodistal spine; dactylus ventral margin doubly serrate. GNATHOPOD 2 (Fig. 7 G 2). Basis anterior margin straight; carpus ventrally expanded with long serrate setae. Additional illustrations (Figs 8 – 10) are also provided for future reference.

Common Names

No common names available.

Taxonomic Hierarchy

Kingdom: Animalia

Phylum: Arthropoda

Class: Malacostraca

Order: Amphipoda

Family: Aoridae

Genus: Grandidierella

Species: Grandidierella pawaiensis Ali-Eimran, Lee & Azman, 2020