Pontonides Borradaile 1917

Genus Pontonides Borradaile, 1917

Type species. Pontonides maldivensis (Borradaile, 1915), by monotypy.

Other species included. P. ankeri n. sp., P. asperulatus Bruce, 2005, P. loloata Bruce, 2005, P. sibogae Bruce, 2005, P. s y m p a t h e s De Ridder & Holthuis, 1979, and P. tatianae n. sp.

Diagnosis. Small to medium-sized shrimps with subcylindrical or depressed body. Carapace smooth, areolate or glabrous; antennal tooth present; hepatic tooth absent; orbits well developed but incomplete; anterolateral angle broadly concave. Rostrum short, toothless, rarely overreaching midlength of intermediate antennular segment. Supraorbital carina, well developed, rectangular or convex, broadly expanding over proximal portion of eyes and forming supraocular eave; reaching to rostrum middle or tip. Orbits well developed but open posterior. Mouthparts with reduced exopods on maxillipeds; second maxilliped with concave distal margin of dactylar segment, ischium with or without fusiform setae; third maxilliped with fusiform setae on basal segment (except in P. maldivensis), with small arthrobranch and distally pointed epipod. First pereiopod with fingers simple and bearing a row of strong setae on tips. Second pereiopods enlarged, unequal, with or without fusiform setae on proximal segments; major chela with surface smooth or covered with small tubercles or papillae, setose; fingers stout, curved; minor chela sparsely setose; fingers long, straight, with curved tips, especially in males. Ambulatory pereiopods with smooth or setose segments; with or without fusiform setae on proximal segments; propodus unarmed; dactylus simple, curved, distally acute. Uropodal exopod with distolateral angle bearing stout movable spine, without distolateral tooth.

Systematic position. Pontonides possesses several synapomorphic features, such as the completely reduced endites of maxilla, the concave dactylar segment of the second maxilliped, and the presence of fusiform setae on the basal segments of the maxillipeds and other appendages, that clearly distinguish it from other genera of the subfamily Pontoniinae. The morphologically most similar genera are Izucaris Okuno, 1999 (Indo-West Pacific, hosts: anemones), differing from Pontonides by the longer rostrum and pointed anterolateral angle of the carapace; Vel eron i a Holthuis, 1951 (eastern Pacific, hosts: gorgonians), differing by the shorter rostrum, closed orbits, and splayed anterolateral angle; Neopontonides Holthuis, 1951 (western Atlantic and eastern Pacific, hosts: gorgonians) differing by the longer rostrum and splayed anterolateral angle; Pseudopontonides Heard, 1986 (western Atlantic, hosts: antipatharians and gorgonians) differing by the presence of a deep pterygostomial notch at the anterolateral angle; Pseudocoutierea Holthuis, 1951 (Atlantic and eastern Pacific, hosts: antipatharians and gorgonians) by differing by the longer rostrum and splayed anterolateral angle; and Chacella Bruce, 1986 (eastern Pacific, hosts: antipatharians) differing by the carapace and abdomen bearing several well developed knobs. Other antipatharian-associated pontoniine genera, such as Dasycaris Kemp, 1922 and Miopontonia Bruce, 1985 (both from the Indo-West Pacific), belong to a distantly related group of genera characterized by the presence of a well developed hepatic spine. Noteworthy, a remarkable host-related convergence in the general body shape may be observed between Dasycaris, Chacella and Ve le ro ni a.

Generic distribution. Tropical Indo-Pacific, from the Red Sea to Japan, Australia, French Polynesia, Hawaii, and the western coast of the Americas (Galapagos and Clipperton islands).