BAL1STES MACROLEPSIS - REDESCRIPTION AND LECTOTYPE DESIGNATION 



31 



and falcate in adults; pectoral fins rounded, 15.4—16.3% SL in 

 juveniles, 10.1% SL in adults; caudal fin rounded in juveniles, 

 double emarginate in adults, its length 23.1-24.3% SL; segmented 

 fin rays of juveniles bearing 1-3 rows of small spinules, these largest 

 on basal part of fins; segmented-fin-ray spinules not apparent in 

 adults. 



Preserved coloration of juveniles (based on BMNH 

 1939.5.24.1849-1850; Fig. 3). Head and body pale brown, paler 

 ventrally; body and caudal peduncle with large (slightly larger than 

 pupil to about twice diameter of eye), pale brown to whitish spots 

 arranged in about six oblique columns; about six spots in anteriormost 

 column (just behind pectoral-fin base), reducing to two spots in 

 posteriormost column (on caudal peduncle); pale spots most con- 

 spicuous on caudal peduncle and posterior part of body; interspaces 

 between spots accentuated with dark grey-brown stripes, bars and 

 (particularly at junctions of bars and stripes) spots, these forming a 

 reticulate pattern; dark grey-brown markings most conspicuous 

 below first dorsal fin, on caudal peduncle and adjacent to bases of 

 anal and second dorsal fins; head with pale spots and irregular 

 markings, these generally smaller and less distinct than those on 

 body; fleshy scale outgrowths mostly unpigmented, except for a few 

 scattered dark grey-brown unbranched outgrowths; first dorsal fin 

 pale brown to hyaline, with three large dark grey spots, one behind 

 each fin spine; second dorsal and anal fins pale brown to hyaline, 

 with large pale spots and dark grey reticulate pattern extending on to 

 basal two thirds of fin; caudal fin pale brown to hyaline, dusky 

 basally near dorsal and ventral edges of fin, with a dusky bar through 

 proximal third of fin; pectoral fins pale brown to hyaline. 



Fedoryako (1981: 22) gave the following description for pre- 

 served juveniles: 'The coloration of preserved specimens up to 100 

 mm [SL] in size is beige with a coarse reticular pattern. The 2nd 

 dorsal, the anal and caudal fins, have large light spots along the 

 margin and the basal part. In large fish [i.e., 1 1 1-177 mm SL] the 

 head and trunk are of a uniform beige, the ventral surface of the head 

 and trunk in front of the pelvic fins is lighter.' 



Live COLORATION OF ADULTS (see Debelius, 1993, 1996;Randall, 

 1995). Head and body grey, shading to pale ventrally; dorsal, anal 

 and caudal fins grey, the distal edges of caudal, anal and second 

 dorsal fins dark grey; pectoral fins dark grey. 



DISCUSSION 



We herein designate the larger syntype of Balistes macrolepis 

 (BMNH 1 887. 11.11 .334, 457 mm SL) lectotype of the species. 



Species of Canthidermis are pelagic, only coming into shallow 

 areas to breed, whereupon demersal eggs are laid in a large pit in 

 sand and/or rubble (Fig. 2). Juveniles are usually found in associa- 

 tion with floating debris and vegetation; Fedoryako (1979: 986; 

 1981: 21) indicated that the type specimens of C. villosus were 

 collected near the surface beneath 'floating microphytes.' Presum- 



ably, juveniles are camouflaged by their spotted/reticulate colora- 

 tion and branched, fleshy scale outgrowths. Current evidence suggests 

 that C. macrolepis breeds in Oman from at least July to November. 

 J. P. Hoover has photographed adults of the species in shallow areas 

 in Oman during the months of July and September, and J.K.L. Mee 

 (pers. comm.) informed us that adults are commonly caught by 

 hook-and-line fishermen working in shallow areas off Muscat around 

 October to November. Interestingly, although taste tests conducted 

 by Omani fisheries researchers indicate that the species is one of the 

 most flavoursome of Omani fishes, Omani fisherman usually dis- 

 card their catches believing the species to be poisonous, or at least 

 inedible (J.K.L. Mee, pers. comm.). 



Acknowledgements. We are grateful to H. Debelius and J. P. Hoover for 

 making photographs of Canthidermis macrolepis available to us, and to 

 J.K.L. Mee for helpful discussions. We thank P. Hurst of the Photographic 

 Unit of the Natural History Museum for the photograph of the lectotype 

 reproduced in Fig. 1. PC. Heemstra kindly loaned comparative materials of 

 Canthidermis from various western Indian Ocean localities. We thank A. -M. 

 Woolger and S. Davidson for preparing radiographs of specimens, and O.A. 

 Crimmen for assistance in locating the syntypes of Balistes macrolepis. We 

 are grateful to J.B. Hutchins, K. Matsuuraand D.J. Siebert for their construc- 

 tive reviews of the manuscript. 



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