Ingolfiella moluccensis Vonk & Jaume 2013, sp. nov.
Creators: name: Vonk, R.
name: Jaume, D.
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Ingolfiellida
Ingolfiellidae
Ingolfiella
Ingolfiella moluccensis

description: Ingolfiella moluccensis sp. nov.   
(Figs. 2–6)  
  Material examined.  — Collected by R. Vonk and Mr. Sumadijo, 9 Nov.2009. Northern beach of Pulau Lelei, Gura Ici islands, northern Moluccas (0°01'38.64"N, 127°14'38.53"E). Holotype: Preparatory female [= with non-setose oöstegites] 1.57 mm, completely dissected and mounted on single slide (MZB, Cibinong). Paratypes: Two males of 1.39 mm (MZB) and 1.43 mm (RMNH, Leiden) and five preparatory females 1.55, 1.55, 1.59, 1.62, and 1.34 mm (ZRC of RMBR, Singapore); all preserved in single 70% ethanol vial.   
  Diagnosis.  — Basis of P5 with proximolateral lobe. Medial margin of coxa V modified, produced ventrally into ridge; ridge sexually-dimorphic, rounded in female, acutely pointed in male. Cephalic ("ocular") lobes present. Dactylus of gnathopods provided with four denticles along posterior margin. Medial surface of protopod of U2 with three denticle combs. Unguis of P3–P4 trifid; that of P5–P7 bifid. Pleopods I–III present in both sexes. Male G2 with bifid robust seta close to palm margin; no modified reverse seta on posterior margin of carpus; merus provided with long hyaline frill extension posterodistally. Male U2 protopod with basofacial robust seta. Oöstegites on P3–P4 only.   
  Etymology.  — Species name refers to its currently known distribution, the Moluccas in Indonesia.   
  Distribution.  — Known so far only from the type locality.   
  Description of female.  — Body (Fig. 2A) vermiform, unpigmented, body somites smooth except for sparsely set simple setae distributed as in Figs. 2A, 3A, 6A, C. Head (Figs. 2A, 3A) clearly longer than broad and more than twice as long as pereionite I, with weakly protruding rostrum; lateral lobes and post-antennal sinus each hardly developed; cephalic ("ocular") lobe not overreaching second segment of antennal peduncle. Epimeral plates on pleonites I–III hardly developed as postero-ventral rounded extensions each crowned with simple seta (Fig. 2A).   
Antennule (Fig. 3A) peduncle segments 1–3 progressively shorter towards distal, length ratio as 1:0.38:0.34. Flagellum 4-articulate, shorter than peduncle segments 2–3 combined; proximal article unarmed, distal longest; articles 2–4 each provided with aesthetasc, aesthetascs progressively shorter towards distal. Accessory flagellum 3-articulate, shorter than two proximal articles of main flagellum combined.  
Antenna (Fig. 3A) slightly shorter than antennule; gland cone short, hardly protruding dorsomedially; protopodal segments 3–5 progressively shorter towards distal, length ratio as 1:0.81:0.76; fourth segment with exceedingly long (as long as fifth protopodal segment), simple robust seta with rounded tip placed subdistally on posterior margin. Flagellum 5-articulate, shorter than protopodal segments 4–5 combined. Labrum and paragnaths (not figured) ordinary, latter lacking inner lobes.  
Mandibles with molar process non-triturative, spiniform. Left mandible (Fig. 3C) incisor subrectangular, cutting-edge irregularly multi-denticulate; lacinia subrectangular, as broad as incisor, cutting edge 5-denticulate; spine row consisting of three pectinate elements plus ca. four tiny pointed processes; spiniform molar process finely serrated. Right mandible (Fig. 3D) with 7-denticulate incisor and finely multi-denticulate lacinia, latter constricted basally; spine row reduced to three short rounded bulges; spiniform molar process apparently smooth.  
Maxillule (Fig. 4D) coxal endite [= inner lobe] with three simple setae; basal endite [= outer lobe] with six robust setae of which one bicuspidate, other 3-cuspidate, other 4-cuspidate, two (longer) 7- and 8-cuspidate, respectively, and one (innermost) comb-like; endopod [= palp] 2-segmented, proximal segment unarmed, distal with two setae 3- and 4-cuspidate, respectively.  
Maxilla (Fig. 3E) with short, subequal blunt plates, each bearing five distal setae; three out of setae on outer plate sparsely setulose.  
Maxilliped (Fig. 3F) basal endite slender, finger-like, with two simple setae; ischium with three simple setae on inner margin; merus, carpus, and propodus each with single simple seta on medial margin; propodus with row of long setules on outer margin; dactylus (Fig. 3G) short, subtriangular, with simple robust seta proximally on outer margin, pinnate distomedial seta, and long (longer than segment) unguis.  
Coxal gills present on P3–P5, ovoid, only that on P5 clearly stalked (Fig. 5A–C). Oöstegites (Fig. 5A, B) on P3–P4, short, subrectangular, shorter than corresponding coxal gill, with three short pointed processes (regressed setae suggesting preparatory female condition?) on distal margin; that on P3 with short simple seta subdistally. Oöstegites of paratype of 1.34 mm reduced and smooth, suggesting specimen probably juvenile.  
Gnathopod I (Fig. 4A) carpo-subchelate, carpus 2.5 times as long as broad, with three short, apparently bifid flagellate robust setae along lateral side of palm margin, stout simple robust seta on palm angle, and two shorter stout simple setae and broad triangular spine on medial surface of segment as figured; palm margin strongly oblique, straight and smooth; posteromedial surface of carpus with excavation apparently to accommodate distal portion of unguis. Dactylus with four slender denticles along posterior margin.  
Gnathopod II (Fig. 4B) carpo-subchelate, carpus massive, shorter (attaining only 88% of length) and stouter (twice as long as broad vs 2.5 times) than carpus of G1; palm margin strongly convex, sparsely serrated, lined up with three apparently unicuspidate short, flagellate robust setae along lateral side; palm angle marked by stout, slightly curved simple robust seta; medial surface of segment with short, stout simple robust seta and strong triangular spine as figured; posteromedial surface of carpus with excavation apparently to accommodate distal portion of unguis. Dactylus with four denticles along posterior margin, spines stouter than G1 counterparts.  
Pereiopods III–IV subequal except for slightly longer propodus and stouter flagellate robust subdistal seta on posterior margin of carpus in P4 (compare Fig. 5A, B). Dactylus subquadrangular, posterodistal angle spur-like, with short simple robust seta partially embedded into hyaline sheath (see inset of Fig. 5A). Unguis shorter than dactylus, tricuspidate.  
Pereiopods V–VII (Fig. 5C–E) progressively longer towards posterior; basis of P5–P6 broad, that of P7 slender; each with dactylus provided with two stiff simple setae on distomedial angle; unguis bifid, with strong triangular tooth subterminally on lateral margin. Basis of P5 (Fig. 5C; arrowed) strongly modified, with rounded outgrowth proximally on outer margin; coxa also peculiar, with medial margin strongly produced ventrally into rounded ridge (see Fig. 6D). Pereiopod VII with one of distal armature elements on distolateral angle of carpus modified into comb-like robust seta provided with proximal spur (see inset of Fig. 5E).  
Pleopods as in male (Fig. 6C), foliaceous, unarmed, members of each pair appressed medially, with straight medial margin and evenly rounded lateral margin. Distomedial angle of pleopods II & III produced into short rounded process, that of pleopod I indistinct.  
Uropod I (Fig. 2B, C) protopod long and slender, subrectangular, with two simple setae on anterolateral [= ventrolateral] margin and simple seta subdistally on posterolateral [= dorsolateral] margin. Exopod unsegmented, much shorter than endopod, acuminate, with simple seta placed at ca. three-fifths length of outer margin. Endopod with short terminal spine plus row of four stout triangular robust setae subterminally; nine setae disposed on segment as figured. Medial surface of protopod adorned with patch of tiny pointed denticles; that of endopod with series of crescent scales (Fig. 2C).  
Uropod II (Fig. 2D) protopod bearing three oblique combs of large denticles on medial surface; denticles apparently triangular but with variably frayed tips (see Fig. 2E); six simple setae distributed on segment as figured, plus row of long setules along posterolateral margin. Rami tapering, exopod stouter and slightly shorter than endopod, more inflated basally, provided with one stout simple seta on medial surface and slender simple seta on dorsolateral margin. Endopod with five simple setae distributed as figured.  
Uropod III (Fig. 2F) tiny, uniramous, protopod subquadrate, with simple seta provided with hyaline process on distolateral angle, plus another one midway of distoventral margin of segment. Exopod much shorter than protopod, acuminate, with long simple seta provided with hyaline process placed subterminally on lateral margin of segment.  
Telson (Fig. 2G) entire, fleshy, globose (see Fig. 2A), about as long as broad in dorsal aspect, distal margin evenly rounded; armature reduced to two long simple setae provided with hyaline process subdistally and two pairs of short penicillate setae, all disposed dorsally as figured.  
  Description of male.  — None of the male specimens seem to display penile papillae, and contrary to most species, their first pair of pleopods appears undifferentiated with respect to the rest of pleopods and also with those of the female. Both features suggest these two males are juveniles. In any case, relevant differences with respect to the female—aside of body size (see material examined)—pertain to the antennule, gnathopod II, coxal plate V and uropod II. Thus, the male antennule (Fig. 3B) displays the proximal article of the main flagellum expanded basally and provided with a long aesthetasc (vs article unarmed in the female).   
The male G2 (Fig. 4C) has a foliaceous hyaline frill implanted close to the posterodistal angle of merus, on medial surface of segment (vs frill absent in female). The carpus wears only two short flagellate robust setae along the palm margin (vs three in the female), whereas the robust seta present on the medial surface of this segment is strongly modified, stout and broadly expanded distally, forked (vs small and simple in the female). In addition, the excavation present on the posteromedial surface of segment (to accommodate unguis) is much more pronounced here than in the female.  
The medial margin of the coxa of P5 (Fig. 6A, B) is acutely produced (vs ridge rounded in female).  
The U2 (Fig. 2H) protopod has a stout basofacial robust seta with reflexed tip (absent in female). In addition, the setae on the medial surface of endopod are swollen basally (vs ordinary in female).
description: Published as part of Vonk, R. & Jaume, D., 2013, A New Ingolfiellid Amphipod Crustacean From Sandy Beaches Of The Gura Ici Islands, Western Halmahera (North Moluccas), pp. 547-560 in Raffles Bulletin of Zoology 61 (2) on pages 552-558, DOI: 10.5281/zenodo.5352412