Fennera holthuisi Marin, 2011, sp. nov.
Creators: name: Marin, Ivan
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Palaemonidae
Fennera
Fennera holthuisi

description: Fennera holthuisi sp. nov.
(Figs. 5–7, 8 d–f)
Type material. Holotype: non-ovigerous mature female (FLMNH UF 26315), French Polynesia, Moorea, outer reef slope, 17˚29’02”S, 149˚52’09’W, 10 m, in Pocillopora, coll. M. Leray, 18 May 2009.
Description. Holotype, female. Small-sized pontoniine shrimp with cylindrical slightly depressed body. Carapace swollen, smooth, armed with several sharp teeth along lower orbital margin (Fig. 6 a). Rostrum short, reaching to distal margin of basal antennular segment, pointing distally, compressed, turned forward; dorsal rostral carina well developed, extending onto carapace, with 4 sharp dorsal teeth, with 2 proximal teeth situated posterior to level of orbit (Fig. 6 a); ventral rostral carina poorly developed, unarmed; proximal lateral rostral lamina feebly developed (Fig. 6 a, b). Orbit well developed, deep, with lower margin armed with 5 small sharp teeth turned forward; inferior orbital angle bluntly produced forward. Pterygostomial angle bluntly rounded.
Abdominal somites smooth; pleura of abdominal somites I–V rounded (Fig. 5). Telson about 2.5 times as long as proximal width, narrowing distally, with 2 pairs of slender dorsal submarginal spines at 0.25 and 0.7 of telson length; distal margin of telson armed with 3 pairs of spines including pair of short stout lateral spines, long robust, hook-like intermediate spines and pair of slender median spines.
Eyes (Fig. 6 b) well developed, large; eyestalk smooth and swollen, about as long as wide; cornea large, subovate.
Antennula well developed; basal segment stout, about twice longer than wide, with well developed stylocerite, with distolateral angle bearing large acute triangular tooth, almost reaching to distal margin of next segment; submarginal ventral tooth absent; intermediate segment stout, slightly wider than long; distal segment stout, as long as wide; proximal part of upper antennular flagellum with 5 or 6 separate segments, shorter ramus with 2 or 3 segments.
Antenna well developed, basicerite about twice longer than wide, smooth, without distoventral tooth; scaphocerite wide, about twice longer than maximal width, overreaching antennular peduncle, distolateral tooth well developed, acute, not reaching to distal margin of blade.
Mouthparts characteristic for the genus and as previously described species (see Holthuis, 1951).
Pereiopod I (Fig. 7 a) with relatively stout segments; coxal segment as long as wide, unarmed; basis as long as wide; ischium about twice longer than wide; merus robust, slightly swollen medially, about 3.5 times as long as wide; carpus about 3.5 times as long as wide, equal to length of chela and slightly shorter than merus; propodus about 3 times longer than wide, about 2.5 times longer than fingers, slightly pointed distally; fingers slender (Fig. 7 b, c), about 3 times as long as wide with straight, smooth cutting margins and simple tips.
Pereiopods II dissimilar in shape and unequal size (Fig. 6 c, f, 8a, b); major pereiopod II (Figs. 6 f, 8b) with relatively robust and smooth segments; coxal segment as long as wide, unarmed; basis as long as wide; ischium about 2.5 times longer than wide; merus robust, about 1.5 times longer than wide; carpus triangular, flaring distally, overlapping carpo-propodal articulation, with smooth distal margin (Fig. 6 g–i); palm cylindrical, about 2.5 times as long as wide, swollen in medial part, not expanded ventrally in distoventral part; fingers robust, about 3.5 times shorter than the length of the palm; fixed finger (pollex) (Fig. 6 i) relatively stout, pointed distally, about twice longer than wide, with smooth entire cutting margin and simple sharp curved tip; movable finger (dactylus) relatively stout, flattened, with well marked dorsal carina and lateral lamina (Fig. 6 g, h), with entire smooth cutting margin and simple curved tip; minor pereiopod II with slender segments (Fig. 6 c); coxal segment as long as wide, unarmed; basis as long as wide; ischium about twice as long as wide; merus robust, slightly swollen medially, about 1.5 times longer than wide; carpus about 2.5 times longer than wide, equal to propodus and merus, smooth, unarmed; propodus subcylindrical in proximal and medial parts, flattened distally, about 2.5 times as long as wide, with straight and smooth lateral margins, distodorsal margin with rounded depression covered with numerous minute teeth and simple setae; pollex feebly developed, bluntly rounded distally, flattened, about twice wider than long (Fig. 6 e); dactylus short, about twice wider than long, flattened, with blunt curved tip, with dorsal margin covered with minute teeth and simple setae (Fig. 6 d).
Pereiopod III with smooth robust proximal and slender distal segments (Figs. 6 j, 7d); coxal and basal segments about as long as wide, unarmed; ischium robust, about 1.5 times longer than wide; merus robust, swollen medially, about twice longer than wide; carpus about 2.2 times longer than wide, about 1.5 times shorter than propodus and merus; propodus relatively robust, pointed distally, about 4.5 times as long as proximal its width, with smooth unarmed margins; dactylus (Fig. 7 e) simple, with proximal rounded ventral protuberance and simple slender and curved unguis. Pereiopods III–V similar.
Pleopods normal, without specific features. Uropods normal, without specific features, slightly exceeding telson; distolateral margin of uropodal exopod with slender spines only.
Differential diagnosis. The new species clearly differs from Fennera chacei in the shape of minor pereiopod II, the form of dactylus of major pereiopod II and the proportions of distal segments of the ambulatory pereiopod III (see Fig. 8). So, segments of minor pereiopod II are relatively slender in F. chacei while distal segments are robust in F. holthuisi sp. nov. (Fig. 8 a, d) as well as fingers less marked dorsally in the latter species. The dactylus of major pereiopod II has well a marked dorsal carina in F. chacei (Fig. 8 b) while the dactylus is flattened, without or with a feebly marked dorsal carina, and well marked lateral lamina in F. holthuisi sp. nov. (Fig. 8 e). The distal segments of pereiopod III, namely the carpus and, especially, the propodus, are markedly thinner in F. chacei (see. Fig. 8 f) than in F. holthuisi sp. nov. (Fig. 8 c).
Etymology. The species named after the famous Dutch carcinologist Dr. Lipke Bijdeley Holthuis (1921–2008) who described the first species of the genus as well as the genus itself.
Distribution. The species is presently known only from the type locality, Moorea, French Polynesia.
description: Published as part of Marin, Ivan, 2011, Fennera holthuisi sp. nov., a new coral-associated pontoniine shrimp (Decapoda: Palaemonidae: Pontoniinae) from Moorea, French Polynesia, pp. 29-39 in Zootaxa 2890 on pages 34-38, DOI: 10.5281/zenodo.201482