Protodulichia scandens Ariyama and Hoshinoi 2019, sp. nov
Creators: name: Ariyama, Hiroyuki
name: Hoshino, Osamu
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Amphipoda
Dulichiidae
Protodulichia
Protodulichia scandens

description: Protodulichia scandens Ariyama and Hoshinoı sp. nov.
(Figures 1 – 5)
[Japanese name: Bōnobori-yokoebiı new]
Type locality
Akinohama Beachı Izu Oshima Island (Oshima Town)ı Tokyo Prefectureı Japanı 34°47 ʹ 15 ” Nı 139°24 ʹ 31 ” Eı 25 m depth.
Material examined
Holotype. Male (OMNH-Ar-11171)ı 2.8 mmı Akinohama Beachı Izu Oshima Island (Oshima Town)ı Tokyo Prefectureı 25 m depthı coarse sand bottomı 13 June 2017ı coll. O. Hoshino. Paratypes: 2 males and 1 ovigerous female (OMNH-Ar-11172 – 11174)ı 3.0ı 2.4ı 3.1 mmı same data as holotype; ovigerous female (OMNH-Ar-11175)ı 2.7 mmı same locality as holotypeı 11 June 2017ı coll. O. Hoshino.
Description
Male [based on holotypeı 2.8 mm (OMNH-Ar-11171)ı and paratypeı 3.0 mm (OMNH Ar-11172) for mandible]. Body (Figure 1) smooth; headı dorsal margin roundedı lateral cephalic lobe trianguları posteroventral margin with small projectionı eyes about 0.4 times as long as head; pereonite 7ı posterodistal margin rotated posteriorly; pleonal epimera roundedı smooth; urosomite 1 not longı about 115% length of pleonite 3.
Antenna 1 (Figure 2 (aıa1)) with ratio of lengths of peduncular articles 1 – 3 1:1.2:0.95ı peduncular article 1 without ventral robust setae; accessory flagellum 2-articulate; primary flagellum with 6 articlesı posterior margin bearing aesthetascs. Antenna 2 (Figure 2 (b)) about 1.3 times length of antenna 1; peduncleı ratio of lengths of articles 3 – 5 1:2.35:3.55ı posterior margin sparsely setose; flagellum slenderı with 4 articlesı terminal article minute.
Upper lip (Figure 2 (c)) broadı fleshyı ventral margin with minute setae. Mandible (Figure 2 (dıd1ıd2ıeıe1ıe2))ı incisor with 4 and 5 cuspsı lacinia mobilis with 3 and 4 cusps in left and rightı respectivelyı 3 wide accessory blades present in both sides; molar developedı with spatula-like process; palpı length ratio of articles 1 – 3 1:2.5 – 2.6:2.0 – 2.1ı articles 2ı 3 setose. Lower lip (Figure 2 (f)) with well-developed inner lobesı outer lobes each with mandibular lobeı distal margins covered with thin setae. Maxilla 1 (Figure 2 (gıg1))ı inner plate long trianguları without setae; outer plate bearing 9 terminal robust setae distally; palp 2-articulateı article 2 bearing 5 robust setae apically and several setae dorsally. Maxilla 2 (Figure 2 (h))ı both plate with distal setaeı inner plate lacking mediofacial row of setae. Maxilliped (Figure 2 (iıi1))ı inner plate with 3 short ventrodistal robust setae; outer plate bearing 8 marginal robust setae mediodistally; palp consisting of 4 articlesı article 2 longı article 4 with slender nail.
Gnathopod 1 (Figure 3 (a))ı coxa longer than wideı posteroventral corner with small notch; basis slightly curved anteriorly; posterodistal margin of merus and posterior margin of carpus setose; propodus setose mediallyı posterior margin with several thick setae; dactylus longı slender. Gnathopod 2 (Figure 3 (bıb1))ı coxa subtrapezoidalı posteroventral corner with small notch; basis with anterolateral ridge; merus posterodistal margin setose; carpus trianguları posterodistal corner setose; propodus largeı about 1.85 times length of carpusı palm smoothı bearing 6 robust setae; dactylus narrow.
Pereopods 3ı 4 (Figure 2 (cıc1ıd)) subsimilar to each other; coxae subquadrateı posteroventral corner of coxa 4 slightly produced; bases widened in middleı many granules present in each gland; meri – dactyli slender. Pereopod 5 (Figure 2 (eıe1)) shorter than pereopod 4; coxa wideı bilobedı both lobes each with robust seta; basis subovateı length about 1.65 times widthı anterior margin with lateral ridgeı posterodistal corner expanded; carpus and merus each bearing several robust setae. Pereopod 6 (Figure 3 (fıf1)) about 1.25 times length of pereopod 5; coxa narrowı bilobedı anterior lobe with robust seta; basis ovalı length about 1.4 times widthı anterior margin with lateral ridgeı posterodistal corner widely expanded; carpus and merus each with several robust setae. Pereopod 7 (Figure 4 (a)) about 1.55 times length of pereopod 6; coxa roundish triangular; basis narrowed distallyı length about 1.75 times widthı anterior margin with lateral ridgeı posteroproximal corner projectedı posterodistal corner not expanded; carpus – propodus slenderı elongateı each with several robust setae.
Pleopods 1 – 3 (Figure 4 (bıcıd))ı peduncles each with 2 coupling hooksı pleopods 2ı 3 bearing 2 and 4 setaeı respectively; outer rami slightly longer than inner ramiı outer rami with 9ı 10ı 10 articles and inner rami with 8ı 8ı 9 articlesı respectively.
Uropod 1 (Figure 4 (e))ı peduncle with 3 dorsomedial robust setaeı mediodistal corner slightly projected; outer ramus about 0.9 times as long as peduncleı about 0.8 times length of inner ramusı outer ramus with 4 dorsalı 2 subterminal and 1 terminal robust setaeı inner ramus bearing 5 dorsomedialı 2 subterminal and 1 terminal robust setae. Uropod 2 (Figure 4 (f)) about 0.75 times length of uropod 1; peduncle mediodistal corner slightly projectedı with robust seta; outer ramus about 1.3 times as long as peduncleı about 0.65 times length of inner ramusı outer ramus with 3 dorsal and 1 terminal robust setaeı inner ramus bearing 4 dorsomedial and 2 terminal robust setae. Uropod 3 (Figure 4 (g)) about half length of uropod 2; peduncle laterodistal corner slightly projectedı medial margin with seta; outer ramus about 2.05 times as long as peduncleı about 0.9 times length of inner ramusı outer and inner rami with 0 – 1 dorsal and 2 dorsomedial robust setaeı respectivelyı both rami each bearing minute terminal robust seta. Telson (Figure 4 (h)) smoothı without setaeı length about 1.3 times widthı dorsodistal end slightly produced.
Ovigerous female [based on paratypeı 3.1 mm (OMNH-Ar-11174)]. Gnathopod 2 (Figure 4 (iıi1))ı coxa largeı anterior margin swollen in middleı posteroventral corner without notch; basis with anterolateral ridge; merus posterodistal margin setose; carpus longish trianguları posterior margin setose; propodus slenderı about 1.2 times length of carpusı palm smoothı bearing 4 robust setae; dactylus longı slender.
Variation. Uropod 3ı outer and inner rami with 0 – 1 and 1 – 2 dorsal robust setaeı respectively (Table 1)ı minute terminal robust seta present on each ramus in all specimens.
Colouration in life
Male (Figure 5 (a)): whole body light red and whiteı eyes silver. Female (Figure 5 (b)): head pale orangeı anterior pereonites dark redı other parts of body almost whiteı eyes silver.
Distribution
Known only from the type locality.
Ecology
This new species builds a mast and clings to the mast on a coarse sand bottom at a depth of 25 m (Figure 5). The mast is about 6 – 7 mm in length and light grey in colourı and several sand grains are attached on. Such behaviour was observed only in the family Dulichiidae (e.g. Mattson and Cedhagen 1989; Neretin et al. 2017)ı and this is the first record in the other amphipods.
Etymology
From the Latin scandens (= scandentı climbing)ı referring to the ecology.
description: Published as part of Ariyama, Hiroyuki & Hoshino, Osamu, 2019, A new superfamilyı familyı genus and species of marine amphipodı Protodulichia scandensı from Japan (Crustacea: Amphipoda: Senticaudata: Corophiida), pp. 2467-2477 in Journal of Natural History 53 (39) on pages 2470-2476, DOI: 10.1080/00222933.2019.1704588, http://zenodo.org/record/3666407