SMITHIANA Publications in Aquatic Biodiversity Bulletin 3 August 2004 Revision of the Indian Ocean Dottyback Fish Genera Chlidichthys and Pectinochromis (Perciformes: Pseudochromidae: Pseudoplesiopinae) Anthony C. Gill and Alasdair J. Edwards Published by the South African Institute for Aquatic Biodiversity Margaret Mary Smith (1916 - 1987), James Leonard Brierley Smith (1897 - 1968) with their dog, Marlin The publication series (Monographs, Bulletins & Special Publications) of the SAIAB (formerly the JLB Smith Insitute of Ichthyology), in its new format honors James Leonard Brierley Smith and Margaret Mary Smith with the name Smithiana, in rec- ognition of their many years of devoted service to African aquatic biology. Their life’s work, a team effort, established modern ichthyology in southern Africa and laid the groundwork for the expansion of aquatic biology throughout the region. © 2004, The South African Institute for Aquatic Biodiversity, Grahamstown, South Africa Front cover photograph: Scales of a preserved coelacanth specimen by James Stapley. © James Stapley, 2002 Revision of the Indian Ocean Dottyback Fish Genera Chlidichthys and Pectinochromis (Perciformes: Pseudochromidae: Pseudoplesiopinae) Anthony C. Gill1 & Alasdair J. Edwards2 ABSTRACT Chlidichthys Smith includes the following 13 species: C. abruptus Lubbock (St Brandon’s Shoals); C. auratus Lubbock (Red Sea); C. bibulus (Smith) (east coast of Africa, Aldabra and Socotra); C. cacatuoides Gill & Randall (Socotra and southern Oman); C. chagosensis new species (Chagos Archipelago); C. clibanarius new species (Comoro Ids, Madagascar and Aldabra); C. foudioides new species (Rodrigues); C. inornatus Lubbock (Maldive Ids and Sri Lanka); C. johnvoelckeri Smith (Comoro Ids and Tanzania to Mozambique, East Africa); C. pembae Smith (Comoro Ids and Tanzania to Natal, East Africa); C. randalli Lubbock (Mauritius); C. rubiceps Lubbock (Red Sea); C. smithae Lubbock (Mauritius). Pectinochromis Gill & Edwards includes a single species: P. lubbocki (Edwards & Randall) (Red Sea). 1 Fish Research Group, Department of Zoology, The Natural History Museum, Cromwell Road, London SW7 5BD, U.K. Present address: School of Life Sciences, PO Box 874501, Arizona State University, Tempe, AZ 85287-4501, USA. 2 School of Biology, Ridley Building, University of Newcastle, Newcastle upon Tyne NE1 7RU, U.K. CONTENTS Introduction .................................................................................................................................................. 1 Materials and Methods ............................................................................................................................... 1 Chlidichthys Smith ........................................................................................................................................ 3 Key to species of Chlidichthys ......................................................................................................... 4 Chlidichthys abruptus Lubbock ........................................................................................................ 5 Chlidichthys auratus Lubbock .......................................................................................................... 7 Chlidichthys bibulus (Smith) ............................................................................................................. 9 Chlidichthys cacatuoides Gill & Randall ....................................................................................... 11 Chlidichthys chagosensis new species ........................................................................................... 14 Chlidichthys clibanarius new species ............................................................................................ 15 Chlidichthys foudioides new species ............................................................................................. 17 Chlidichthys inornatus Lubbock ..................................................................................................... 19 Chlidichthys johnvoelckeri Smith.................................................................................................... 20 Chlidichthys pembae Smith ............................................................................................................. 22 Chlidichthys randalli Lubbock ....................................................................................................... 25 Chlidichthys rubiceps Lubbock ....................................................................................................... 26 Chlidichthys smithae Lubbock ........................................................................................................ 27 Pectinochromis Gill & Edwards .................................................................................................................29 Pectinochromis lubbocki (Edwards & Randall).............................................................................. 29 Acknowledgements ................................................................................................................................... 32 References ................................................................................................................................................... 32 Revision of the Indian Ocean Dottyback Fish Genera Chlidichthys and Pectinochromis (Perciformes: Pseudochromidae: Pseudoplesiopinae) Anthony C. Gill & Alasdair J. Edwards INTRODUCTION the caudal peduncle at the vertical through the posterior edge of the dorsal hypural plate. Head length was The Pseudoplesiopinae is one of 4 subfamilies measured from the snout tip to the posteriormost edge of recognised in the Indo-Pacific fish family the opercular membrane. Snout length was measured Pseudochromidae. They are distinguished from members over the shortest distance from the snout tip to the orbital of the other subfamilies (Anisochrominae, rim, without constricting the fleshy rim of the latter. Orbit Congrogadinae and Pseudochrominae) in having a single diameter was measured as its fleshy horizontal length. tubed lateral-line scale, which is positioned just behind Interorbital width was measured as the least fleshy the gill opening. Of the 4 subfamilies, the width. Upper jaw length was measured from the snout Pseudoplesiopinae is the least known subfamily tip to the posterior edge of the maxilla. Predorsal, preanal taxonomically, despite being well represented in and prepelvic lengths were measured from the snout tip museum collections. The present study is our second in to the base of the first spine of the relevant fin. Body a series of papers that aim to revise the width was measured between the posttemporal pores Pseudoplesiopinae. In the first paper (Gill & Edwards, (Fig. 1). Caudal peduncle length was measured from the 1999), we provided an historical review of the base of the last anal-fin ray to the ventral edge of the systematics of the Pseudoplesiopinae, cladistically caudal fin at the vertical through the posterior edge of diagnosed the subfamily and its 5 included genera, and the ventral hypural plate. Caudal peduncle depth was proposed a scheme of intergeneric relationships. The aim measured obliquely between the bases of the last dorsal- of the present paper is to revise 2 of the genera, and last anal-fin rays. Measurements of fin rays Chlidichthys Smith and Pectinochromis Gill & Edwards. excluded any filamentous membranes. Pectoral fin length Our intention is to revise the remaining 3 genera was measured as the length of the longest middle ray. (Amsichthys Gill & Edwards, Lubbockichthys Gill & Caudal fin length was measured as the length of the Edwards, and Pseudoplesiops Bleeker) in future papers. lowermost ray on the dorsal hypural plate. The genera revised in the present paper represent a Frequency distributions for selected meristic convenient grouping among pseudoplesiopines. They characters are given in Tables 1-15. Counts of dorsal-, are sister taxa, sharing 5 unequivocal synapomorphies: anal- and pelvic-fin spines (unsegmented rays) and 3 epurals; infraorbital 2 reduced or absent; laterosensory- segmented rays are presented, respectively, as Roman canal-bearing bones weakly developed; second and Arabic numerals. If the last dorsal- or anal-fin ray preopercle pore absent; and 10 precaudal vertebrae (Gill was divided at its base it was counted as a single ray. & Edwards, 1999). They are also geographically distinct Counts of branched, segmented rays in the dorsal and in being restricted to the western and central Indian anal fins included unbranched rays behind the first Ocean (including the Red Sea); the remaining branched ray. A value was not recorded if, due to tip pseudoplesiopine genera occur only marginally in the damage, a branched or unbranched condition could not central Indian Ocean, and are otherwise restricted to the be determined for the segmented ray preceding the eastern Indian and Pacific Oceans. anteriormost branched ray. As in most actinopterygian fishes, the upper ray in the pectoral fin is rudimentary MATERIALS AND METHODS and rotated so that its asymmetrical medial and lateral hemitrichs appear to represent 2 separate rays; these were Specimens examined are listed under Material Examined counted as a single ray. Procurrent caudal-fin ray counts for each species; institutional codes follow Leviton et al. were of the rays above (“upper”) and below (“lower”) (1985). Lists of paratypes of new species are arranged the principal caudal-fin