Review of the Pipefish Genus Corythoichthys with Description of Three New Species

Abstract

The pipefish genus Corythoichthys is diagnosed and a key is provided for the 10 recognized Indo-Pacific species. Each species is figured, diagnosed, described and its distribution (based on examined material) is discussed. Several species exhibit west to east clinal variation in counts of tail rings, subdorsal rings or dorsal-fin rays; north-south variation may also occur. Preserved coloration is often highly variable, but locally dominant patterns are found in some forms; characteristic markings persist on venter of anterior trunk rings of all species. Modal trunk-ring frequencies indicate four principal species groups. Corythoichthys amplexus (15 rings) is recorded from the Indian Ocean (Amirantes, Seychelles, Ceylon) and from western Pacific localities, including Australia (Queensland) and Samoa. Modally 16 ring species are C. flavofasciatus, C. intestinalis, C. nigripectus, C. ocellatus and C. schultzi. C. flavofasciatus and C. schultzi are widely distributed from the northern Red Sea to the central Pacific, but the former is apparently absent from Australian waters. C. nigripectus occurs in the Red Sea and Pacific Ocean (Carolines to Society Is.), but is presently unknown from the Indian Ocean; C. ocellatus and C. intestinalis are known only from western and/or central Pacific collections. The 17 trunk-ring group includes C. haematopterus, the generic type, and two new species, C. insularis (Comore and Amirante Is.) and C. polynotatus (Palau and Philippine Is.). C. haematopterus, apparently absent from the Red Sea and Australia, ranges from E. Africa to the New Hebrides. The 18 trunk-ring group is represented by an Australian Great Barrier Reef endemic, C. paxtoni n. sp. Western Atlantic species (albirostris Kaup, brachycephalus Poey, profundus Herald) heretofore included in Corythoichthys are provisionally referred to the catchall genus Syngnathus. Hippichthys heptagonus Bleeker is shown to be a senior synonym of Syngnathus djarong Bleeker; Hippichthys Bleeker, 1849, therefore takes precedence over Bombonia Herre, 1927 (type species: Syngnathus djarong).