Hamopontonia corallicola Bruce, 1970

Marin, Ivan, 2012, The “ Hamopontonia corallicola ” Bruce, 1970 species complex (Crustacea, Decapoda, Palaemonidae): new records and new species from the Great Barrier Reef, Australia, Zootaxa 3272, pp. 35-56 : 36-39

Hamopontonia corallicola Bruce, 1970

( Figs. 1 , 2 , 9 a, 14A, B, 15B)

Hamopontonia corallicola Bruce, 1970: 41 , figs. 1–4 (type locality: Kat O Ohau, Hong Kong).

Material examined. Australia, GBR, Lizard Island area — 1 ovigerous female (pcl. 3.0 mm), 1 non-ovigerous female (pcl. 2.8 mm), 1 male (pcl. 2.5 mm) (QM W33500) — McGillivray reef, wall, LI10-073, 14°39.509’S 145°29.561’E, 10 m, on Goniopora sp., coll. I. Marin, 0 4 Sept. 2010; 3 ovigerous females (pcl. 4.1, 4.1, 4.0 mm), 3 males (pcl. 2.7, 2.5, 2.3 mm) (QM W33501) — Mermaid Cove — Little Vicky, patch reef, LI10-055, 14°38.852’S 145°27.150’E, 10–12 m, on Goniopora sp., coll. I. Marin, 0 2 Sept. 2010; 1 ovigerous female (pcl. 5.0 mm, tl. 16 mm), 5 ovigerous females (pcl. 4.6, 3.6, 3.4, 3.2, 3.0 mm), 4 males (pcl. 3.0, 2.8, 2.5, 1.5 mm) (QM W33502, W33503) — reef on the left side of Bird Islet, LI10-105, 14°41.571’S 145°27.986’E, 0.5–1 m, on Goniopora sp., coll. I. Marin, 0 8 Sept. 2010; 1 ovigerous female (pcl. 4.6 mm) — reef on the left side of Bird Islet, LI10-105, 14°41.571’S 145°27.986’E, 0.5–1 m, on Turbinaria sp., coll. I. Marin, 0 9 Sept. 2010.

Description. Medium-sized pontoniine shrimp species with smooth subcylindrical body. Carapace swollen, smooth, with antennal tooth, without hepatic tooth. Rostrum long, compressed, acute distally; dorsal rostral carina well developed reaching to 1/3 of the carapace length, rostral formula 1–2 + 5–7/0 ( Fig. 1 a–d); ventral rostral carina feebly developed, toothless. Orbit well developed, deep, unarmed; inferior orbital angle bluntly rounded. Abdominal somites smooth; pleura of abdominal somites I–V rounded ( Fig. 1 a). Telson ( Fig. 1 e) about 4 times as long as proximal width, narrow medially and distally, with 3 pairs of medium submarginal dorsal spines at 0.6, 0.75 and 0.9 of telson length; distal margin of telson armed with two hook-like projections (teeth) and distinct notch medially, notch covered with numerous simple setae. Eyes well developed, large, with cylindrical eyestalk and with ovate cornea. Antennule well developed; basal segment about twice longer than wide, with distolateral angle bearing large acute tooth and small medial convex projection (lobe); with small ventro-mesial tooth. Antenna well developed, basicerite large, about twice as long as wide, without distoventral tooth; scaphocerite wide, about twice as long as maximal width, with well developed acute distolateral tooth not reaching the level of the distal margin of the blade. Pereiopod I with slender unarmed segments; carpus about 6 times as long as wide, about twice length of chela and slightly longer than merus; propodus cylindrical, about twice longer than wide; fingers slender, equal to palm, with straight, smooth cutting margins. Pereiopods II similar in shape and unequal size ( Figs. 1 a). Major pereiopod II ( Fig. 1 a, f) with relatively robust and smooth segments; carpus triangular, flaring distally, overlapping carpo-propodal articulation, with smooth distal margin ( Fig. 1 f, g); palm ( Fig. 1 f) cylindrical, about 4 times as long as wide, slightly swollen in central part; fingers robust, 3 times as long as wide, about 3 times shorter than length of the palm; fixed finger (pollex) with two large teeth in central part; movable finger with large medial tooth. Minor pereiopod II ( Fig. 1 g) similar to major in proportions but smaller in size and more slender, especially in males ( Fig. 1 d). Pereiopod III with smooth robust proximal and slender distal segments; carpus about 2.5 times longer than wide, about half of length of propodus and merus; propodus relatively slender, about 6 times as long as proximal width, with smooth unarmed margins; dactylus simple, with simple, slender, curved unguis. Pereiopods III–V similar. Uropods slender, slightly exceeding telson; distolateral margin of uropodal exopod rectangular with small movable distolateral spine, fixed tooth absent.

Remarks. The examined specimens are clearly similar to the original description of the species given by Bruce (1970). For the difference from other species of the genus see below.

Coloration. Females. Generally body and appendages transparent; cornea and eyestalk brightly white; antennula and antenna transparent with white transverse bands; carapace with medium uniformly white spot situated behind orbital angle, with large dorsal patch consisting of red or orange centrally fringed with white broad band; similar dorsal patches on each of abdominal somites I–III and, sometimes, on abdominal somite IV; pleura and ventral margins of abdominal somites I–IV with large white spots; abdominal somite VI with proximal white transverse band; telson and uropods transparent with distal white markings; chelipeds and ambulatory pereiopods generally transparent with numerous transverse broad white bands and small violet or red dots between the bands. Some color variation is observed for the specimens of the species from the different localities. Thus, two ovigerous females from Taiwan ( Fig. 2 A, B) have large circular orange-white patches on the dorsal surface of abdominal somites I, III and IV while specimens from Australia ( Fig. 2 D–F) mainly possess more narrow bicolor or uniformly white patches on abdominal somites I–III and only a small white marking presents on abdominal somite IV ( Fig. 2 C). At the same time, form of dorsal patches, their coloration and intensity significantly vary in specimens collected from the Lizard Island area ( Fig. 2 C–G). Specimens collected from shallow water (about 1 m depth) colonies of Goniopora sp. are mainly transparent ( Fig. 2 G) while specimens from deeper dwelling colonies of the same coral possess brighter coloration. Probably transparent coloration is related to the problem of concealment of brightly colored body on the surface of shallow water corals; brightly colored animals are probably more visible for predators.

Males. Body and appendages transparent; cornea and eyestalk brightly white; antennula and antenna mainly transparent with several white spots; carapace with large dorsal patch red or orange in the center, fringed with a white band and large white spot situated behind the orbital angle; with similar dorsal patches on abdominal somites I, II, III; pleura and ventral margins of abdominal somites I–IV with large white spots and bands, respectively; abdominal somite VI with white proximal band; telson transparent with distal white band; chelipeds and ambulatory pereiopods generally transparent with numerous transverse white bands and tiny red dots. Coloration of males also varies from very intensive with well marked dorsal and lateral white patches and bands ( Fig. 2 H, I) to less colored ( Fig. 2 J) and completely transparent. Immature individuals are always completely transparent.

Measurements. The largest collected ovigerous female has pcl. 5.0 mm, tl. 16 mm; the largest male — pcl. 3.0 mm, tl. 12.

Host. The species was found in association with different species of the genus Goniopora de Blainville, 1830 (Hexacorallia, Scleractinia , Poritidae ) ( Fig. 14 Ab, B, 15A, B) and once on the surface of a coral of the genus Turbinaria Oken, 1815 (Hexacorallia, Scleractinia , Dendrophyllidae ). Other macrosymbionts found on the surface of Goniopora spp. in the observed area are pontoniine shrimp Periclimenes gonioporae Bruce, 1994 ( Marin & Caley 2011) and syngnathid fish of the genus Bulbonaricus (Pisces, Syngnathidae ), probably belonging to undescribed species.

Distribution. The distribution of the species needs verification as many records of H. corallicola belongs to H. fungicola sp. nov. (see below) or possibly undescribed species associated with actinian host (see above). Presently, the presence of the species is confirmed from Hong Kong (the type locality), Taiwan and the Great Barrier Reef of Australia; probably widely distributed Indo-West Pacific species.

Figures

FIGURE 1. Hamopontonia corallicola Bruce, 1970, ovigerous female, pcl. 3.0 mm, QM W 33500 (a, b, e – g), ovigerous female, pcl. 3.2 mm, QM W 33502 (c), male, pcl. 2.7 mm, QM W 33501 (d): a— general view; b, c— carapace, mesial view; d— carapace and two first pairs of pereiopods; e— telson; f— major pereiopod II; g— minor pereiopod II.

FIGURE 2. Coloration of Hamopontonia corallicola Bruce, 1970: A, B — ovigerous female, pcl. 4.3 mm, NTOU, south Taiwan, Kantin, 12 m, on Goniopora; C — ovigerous female, pcl. 4.6 mm, QM W 33502; D, E — ovigerous female, pcl. 4.1 mm, QM W 33501; F — ovigerous female, pcl. 3.6 mm, QM W 33501; G — ovigerous female, pcl. 5.0 mm, QM W 33502; H, I — male, pcl. 2.7 mm, QM W 33501; J — male, pcl. 1.5 mm, QM W 33502.

FIGURE 9. Hamopontonia corallicola Bruce, 1970 (a) and Hamopontonia physogyra sp. nov. (b – g), front of carapace: a— ovigerous female, pcl. 5.0 mm, QM W 33502; b, c— ovigerous female, pcl. 3.8 mm, QM W 33510; d— ovigerous female, pcl. 4.1 mm, QM W 33510; e— holotype, ovigerous female, pcl. 4.0 mm, QM W 33521; f— male, pcl. 3.0 mm, QM W 33511; g— male, pcl. 3.2 mm, QM W 33521.

FIGURE 14. Pontoniine shrimps of the genus Hamopontonia Bruce, 1970 on their hosts: A, B — Hamopontonia corallicola Bruce, 1970, ovigerous females, on Goniopora sp. (Poritidae); C, D — Hamopontonia physogyra sp. nov., ovigerous female (C) and male (D), on Physogyra lichtensteini Milne-Edwards & Haime, 1851, (Caryophyllidae); E, F — Hamopontonia fungicola sp. nov., ovigerous female (E) and male (F), on Heliofungia actiniformis (Quoy & Gaimard, 1833) (Fungiidae).