Liuomelita mollipalma Yanrong & Zhu & Sha & Ren 2021, sp. nov.
Creators: name: Yanrong, Wang
name: Zhu, Chaodong
name: Sha, Zhongli
name: Ren, Xianqiu
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Amphipoda
Melitidae
Liuomelita
Liuomelita mollipalma

description: Liuomelita mollipalma sp. nov.   
(Figures 1–4)  
 Diagnosis   
Same as that of the new genus.  
 Description   
Based on male holotype specimens.  
Head slightly shorter than pereonites 1 and 2 combined, without rostrum, anterior lobe truncated, lower margin without notch, bearing a large and acute accessory process; eyes present, with pigments reduced in ethanol material.  
Antenna 1 distinctly longer than antenna 2; peduncular article 1 subequal in length to article 2; article 2 is 1.7 times the length of article 3; primary flagellum bearing 25+ articles, few very thin and short setae scattered along flagellum; accessory flagellum 4–5 articulate.  
Antenna 2 slenderer than antenna 1, peduncular article 5 slightly longer than article 4; article 4 is 1.5 times longer than articles 1–3 combined; article 2 with protruding lobe reaching 2/3 length of article 3; flagellum 0.4 times length of peduncle, 11-articulate.  
Mandible with incisor distal margin bearing 5 teeth; lacinia mobilis with 4 teeth on distal margin; 3+ accessory spines present; molar well developed; palp 3-articulate, short, medium reduced, article 3 subequal to article 2, with only 3 slender apical setae, article 2 with 3 slender and 1 plumose marginal setae, article 1 is 1/2 length of article 2.  
Lower lip inner lobes small but well defined, rounded; outer lobes rounded, end margin bearing minute short setae.  
Maxilla 1 inner plate subtriangular, lined with a row of 13 long setae; outer plate elongate, distinctly longer than inner plate, with 9 dentate strong setae apically; palp 2-articulate, article 2 is 2.4 times length of article 1, with a row of 9 slender setae apically, article 1 bearing long plumose setae distally.  
Maxilla 2 inner plate broader than but slightly shorter than outer plate, bearing oblique facial row of setae; outer plate bearing long plumose setae on the tip.  
Maxilliped inner plate with 9 long plumose setae; outer plate reaching 2/3 length of palp article 2, inner margin with a row of robust tooth-like setae; palp 4-articulate, article 4 inner margin with a row of robust setae and patch of short setae along inner side.  
Pereopod 1 (gnathopod 1) not extended distally, without a rounded anterior corner; basis with posterior margin bearing long plumose setae proximally, and transverse row of 4 short setae medially; ischium posterodistal corner with a dense bundle of setae; merus subrectangular, with a row of longer plumose setae along distal margin, and row of short setae on distal half of posterior margin; merus subequal in length to propodus, with 4 transverse rows of long simple setae on anterior margin, a row of long robust setae on distal margin, and dense rows of long plumose setae on posterior margin; propodus suboval, with 4 transverse rows of simple setae along anterior margin, posterior margin bearing dense rows of long plumose setae, palm with row of numerous short simple setae posteriorly; dactylus as long as palm, strongly curved, evenly tapering, with acute tip.  
Pereopod 2 (gnathopod 2) coxa subrectangular (length 2.1 times width), anterior margin slightly convex, gill with indistinct peduncle; basis slightly expanded medially and distally, subequal in length to coxa, with posterior margin bearing long plumose setae and a bundle of short plumose setae distally, anterior margin only with plumose setae distally; merus shorter than carpus, subrectangular, with a small acute protrusion at the posterior distal corner; carpus cup-shaped, distinctly (0.43 times) shorter than propodus, distal margin with row of long plumose setae; propodus with anterior margin nearly straight, with rare long plumose setae on distal half, posterior margin strongly convex, with dense plumose setae on nearly entire length, inner face of palm soft, without seta or protuberance; dactylus shorter than palm, strongly curved, tapering, with acute tip, outer margin bearing 5 transverse rows of short setae on basal half.  
Pereopod 3 coxa slightly longer than coxa 2, rounded distally; basis slightly longer than coxa, with long plumose setae along basal half of posterior margin and rare plumose setae along distal half of anterior margin; ischium with one robust seta posterodistally; merus slightly longer than carpus, with 3 and distally 1 setae on anterior margin, posterior margin only bearing rare plumose setae distally; carpus slightly longer than propodus, with 4 groups of 2–3 robust setae and short plumose setae along posterior margin; propodus narrower than carpus, with 7 groups of 2–3 robust setae and short plumose setae along posterior margin; dactylus curved, evenly tapering, with nail.  
Pereopod 4 coxa subequal in length to coxa 3, posterior margin strongly convex medially; distal articles similar to that of pereopod 3 in shape, but shorter than in length.  
Pereopod 5 shorter than pereopods 6–7, coxa with slightly rounded front margin, with rounded anterior lobe pulled down; basis regular (length 1.4 times width), with posterior wing, anterior margin with small robust setae and group of 3 robust setae distally, posterior margin serrate, posterodistal corner rounded; merus slightly expanded, shorter than carpus, posterior margin with 1 robust seta medially and 3 robust setae distally, anterior margin with only 1 robust seta distally; carpus subequal in length to propodus, anterior margin with 2 robust setae and distally 2 setae, posterior margin with 2 setae distally; propodus narrower than carpus, posterior margin with 3 robust setae and distally a group of 4 setae, anterior margin with 3 groups of 2 or 3 setae and distally a group of 2 setae; dactylus small, with nail.  
Pereopod 6 coxa with rounded anterior lobe pulled down; merus expanded, anterior margin distally with 2 robust setae, posterior margin with 3 and distally 2 robust setae; carpus longer than propodus, anterior margin with 2 groups of 2–3 robust setae and distally 3 robust setae, posterior margin with distally 6 robust setae; propodus anterior margin with 5 groups of 2–3 robust setae and distally 2 setae, posterior margin with 3 groups of 1–3 robust setae and distally 4 robust setae; dactylus small (0.4 times length of propodus), with nail.  
Pereopod 7 similar to pereopod 6, coxa small, without distinct anterior lobe.  
Epimeron plate 1 with oblique crest, posterior margin with 1 large tooth medially and 1 contiguous smaller tooth on each side; hind corner subacute; posterior margin dentate.  
Epimeron plate 2 with oblique crest, ventral margin with 4 simple long setae, posterior margin with 1 large tooth medially and 3 contiguous smaller teeth on each side; hind corner acute; posterior margin dentate, with short simple setae.  
Epimeron plate 3 hind corner produced, acute, posterior margin concave, ventral margin with row of 4 short plumose setae; hind corner acute; posterior margin dentate, with short simple setae.  
Urosomite segment 1 with large blunt mid-dorsal tooth, each side of which bearing acute teeth. Urosomite segment 2 with acute teeth on posterior margin.  
Uropod 1 extending beyond end of uropod 2; peduncle without interramal spur, with 9 robust setae, ventral margin with one robust seta; inner ramus longer than outer ramus, with 11 marginal and 3 distal robust setae; outer ramus with 7 marginal and 2 distal robust setae and long plumose setae.  
Uropod 2 peduncle shorter than rami, with 5 robust setae; inner ramus longer than outer ramus, with 6 marginal and 4 distal robust setae; outer ramus with 6 marginal and 2 distal robust setae and plumose setae.  
Uropod 3 long, peduncle shorter than that of uropod 1–2, with 7 robust setae; inner ramus much (6.2 times) longer than outer ramus, 2-articulate, article 1 with 7 groups of 3–5 marginal and 2 groups of distal robust setae; inner ramus ovoid with 1 robust seta at the tip.  
Telson fully cleft, each part bearing 5 apical robust setae.  
 Sexual dimorphism based on female paratype specimen.   
In structure of pereopod 2 (gnathopod 2). Pereopod 2 in male bigger and stronger than in female; carpus in male shorter than in female; propodus in female not bearing soft area, anterior margin bearing 6 tufts of robust setae, posterior margin bearing long simple setae, palm oblique, with numerous stout robust setae; dactylus as long as palm, curved to inside of propodus, outer margin with several setae, tip acute.  
 Material examined   
 Holotype male. MBM 286558, 10.8 mm, dissected, Okinawa Trough, RY 0108, 126°33′E, 27°47′N, depth 996.9 m, 17 April 2014.   
 Paratype female. 10.3 mm, same collection data as holotype.   
 Additional material. 11 males and females, 8–11 mm, same collection data as holotype. MBM 286156, males and females 7–10 mm, Okinawa Trough, RY 0110, 126°53.8′E, 27°47.4′ N, depth 996.9 m, 17 April 2014.   
 Distribution   
North-West Pacific, Okinawa Trough, hydrothermal vents at 996.9 m depth.  
 Etymology   
 From the Latin moll (= soft), referring to the soft inner surface of propodus of the male pereopod 2.
description: Published as part of Yanrong, Wang, Zhu, Chaodong, Sha, Zhongli & Ren, Xianqiu, 2021, Liuomelita mollipalma, a new genus and species of Melitidae (Amphipoda: Hadzioidea) from hydrothermal vents of the Okinawa Trough, North-West Pacific, pp. 1299-1310 in Journal of Natural History 55 (19 - 20) on pages 1302-1308, DOI: 10.1080/00222933.2021.1947535, http://zenodo.org/record/5467811