A Review of the Monotypic Indo-Malayan Labrid Fish Genus Xenojulis 1
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Pacific Science (1982), vol. 36, no. 1 © 1982 by the University of Hawaii Press. All rights reserved A Review of the Monotypic Indo-Malayan Labrid Fish Genus Xenojulis 1 JOHN E. RANDALL 2 and THOMAS A. ADAMSON 3 ABSTRACT: The labrid fish genus Xenojulis de Beaufort seems most closely related to Macropharyngodon Bleeker, differing principally in the pharyngeal dentition. It consists of a single species, X. margaritaceus (Macleay), which is known from New Guinea, the Philippines, and Western Australia. Xenojulis montillai de Beaufort is a junior synonym based on the terminal male form. THE LABRID FISH GENUS Xenojulis was estab ferent from the teeth of Halichoeres. In our lished by de Beaufort (1939), based on two opinion, Xenojulis is not related to Stethojulis; specimens from the Philippines. One he identi its closest relative is Macropharyngodon fied as X. margaritaceus, a species described by Bleeker (revised by Randall 1978). Further Macleay (1884) (as Platyglossus margari more, we believe that there is but one species taceus) from a single specimen from New of Xenojulis. Guinea, and the other he named X. montillaL We have found only twelve specimens of He designated the latter as the type species Xenojulis in museums: the holotype ofX. mar because of the presumed abnormal dorsal garitaceus (X ray provided) at the Australian spine count of VII for the holotype of X. Museum, Sydney (AMS); one specimen from margaritaceus. the Bernice P. Bishop Museum, Honolulu De Beaufort's description of the genus (BPBM); five from the Natural History Xenojulis was not detailed. Of the relation Museum of Los Angeles County (LACM); one ships to other wrasse genera he wrote, from the U.S. National Museum of Natural "Xenojulis is related to Halichoeres and to History, Washington, D.C. (USNM); and four Stethojulis, perhaps more to the latter than to from the Western Australian Museum, Perth the former" (1939: 418). He differentiated (WAM). The nine largest of these specimens Xenojulis from Halichoeres by its having form the basis for the diagnosis of the genus scales on the thorax and before the dorsal fin and the description of X. margaritaceus not smaller than those on the sides of the below. body. Actually, they are distinctly smaller. He separated Xenojulis from Stethojulis by its dentition. This is certainly correct, but his METHODS description ofthe dentition ofXenojulis needs modification. He stated "the anterior teeth Standard length (SL) is measured from the are much larger than the posterior teeth, form anterior end of the snout in the median line ing well-developed canines. In this respect (either upper lip or upper canines, whichever Xenojulis again agrees with Halichoeres" (de is more anterior) to the base of the caudal fin Beaufort 1939: 419). The large anterior teeth (posterior end of hypural plate). Head length of Xenojulis are not typical canines because is measured from the same anterior point to they are compressed and thus are very dif- the posterior end of the opercular flap. Body depth is the greatest depth from the base ofthe dorsal spines to the ventral margin of the abdomen (correcting for any obvious mal 1 Manuscript accepted 21 September 1981. formation of preservation). Width of body is 2 Bernice P. Bishop Museum, P.O. Box 19000-A, Honolulu, Hawaii 96819. measured immediately posterior to opercular 3 Natural History Museum of Los Angeles County, flap. Orbit diameter is the greatest fleshy dia Los Angeles, California 90007. meter, but interorbital width is the least bony 119 ...... TABLE 1 IV 0 PROPORTIONAL MEASUREMENTS OF SPECIMENS OF Xenojulis margaritaceus EXPRESSED AS PERCENTAGES OF STANDARD LENGTH LACM WAM WAM USNM LACM BPBM WAM WAM 37434-14 P27004-001 P27004-001 224426 37434-14 22747 P25107-011 P25107-011 83.2 9\.4 Standard length (mm) 64.9 66.2 78.0 79.5 80.0 82.2 34.3 38.6 Depth of body 34.1 34.8 36.2 36.4 37.3 36.8 12.0 13.9 Width of body 13.1 13.0 13.2 13.2 12.7 12.8 33.8 34.0 34.1 Head length 35.4 35.2 33.7 33.7 34.8 10.8 1\.0 Snout length I\.9 I \.0 10.8 10.9 11.\ 10.6 6.4 5.8 Orbit diameter 7.1 7.2 6.0 6.0 5.9 6.3 7.2 7.8 Interorbital width 7.2 7.1 7.7 7.3 7.9 7.4 20.6 20.5 Depth of caudal peduncle 19.9 19.3 20.1 20.1 19.8 20.4 10.1 9.6 Length of caudal peduncle 9.5 9.4 9.4 9.9 9.3 9.7 7.1 8.0 Length of first dorsal spine 7.9 7.6 7.6 7.0 7.4 6.8 8.8 9.6 Length of second dorsal spine 9.2 9.4 9.1 8.8 8.9 Broken 9.4 10.1 Length of third dorsal spine 9.6 9.5 9.6 9.4 9.4 8.6 8.5 9.1 Length of fourth dorsal spine 8.5 8.5 9.2 8.2 9.1 8.5 8.5 9.5 Length offifth dorsal spine 9.1 8.6 9.0 7.9 9.8 8.8 13.1 14.0 Length of ninth dorsal spine 13.1 12.7 13.1 12.0 14.4 13.4 2\.4 28.0 Length of longest dorsal ray 18.5 18.6 23.2 24.5 23.0 2\.9 '"tI 6.1 5.5 Length of first anal spine 5.7 5.7 5.6 5.0 6.0 6.1 > 8.7 9.0 (j Length of second anal spine 8.9 8.8 7.7 8.1 9.4 8.6 ...... 13.1 12.1 'TI Length of third anal spine 12.9 12.8 12.6 12.0 14.0 12.8 ...... 18.5 24.9 (j Length of longest anal ray 17.9 18.3 2\.8 2\.4 24.8 20.9 28.8 28.7 28.0 30.4 CIl Length of caudal fin 26.5 27.3 29.2 28.3 (j 19.6 21.3 20.8 ...... Pectoral fin length 20.0 20.9 19.9 19.3 20.0 26.5 23.2 31.5 tTl Pelvic fin length 20.7 27.5 25.6 28.3 27.4 Z ---- (j ,tTl -< a-0 S(1) V> .0'.... !>' ::::l ...!>' '-<...... '0 00 IV The Monotypic Labrid Fish Genus Xenojulis-RANDALL AND ADAMSON 121 width. The depth ofthe caudal peduncle is the REMARKS: The genus Xenojulis is most least depth; the length of the caudal peduncle closely related to Macropharyngodon Bleeker, is measured horizontally between verticals at sharing with it the same fin-ray counts, same the rear base of the anal fin and base of the general shape of the head and body, anterior caudal fin. The lengths of the fin spines and origin of dorsal fin, the short fourth dorsal rays are measured from their distal tips to the spine (not true of all species of Macro extreme bases (the latter determined from X pharyngodon), and the slightly rounded rays). caudal fin. The distinctive dentition of the Pectoral-ray counts include the rudimen jaws, which differentiates it from all the tary upper ray. Gill-raker counts include all species ofHalichoeres, is similar to one species rudiments. Lateral-line scales are counted to of Macropharyngodon, M. kuiteri Randall, the base of the caudal fin. the most divergent species of the genus. The proportional measurements ofTable 1 Xenojulis differs notably from Macro are presented as a percentage of the standard pharyngodon in the pharyngeal dentition length. The same data are given in the text as (in this it is like Halichoeres). The upper ratios ofthe standard length (body depth and pharyngeal teeth of Macropharyngodon are head length), of the body depth (width of dominated by two large molars on each side body), and ofthe head length (other measure preceded by only 4-8 blunt conical teeth; the ments), rounded to the nearest 0.05. lower pharyngeal bone has a single huge median posterior molar with only 1-3 small blunt conical teeth on each side and preceded Xenojulis de Beaufort on median limb by only 5-9 blunt conical Xenojulis de Beaufort, 1939: 415 [type teeth (Randall 1978, fig. 1). Xenojulis differs species, Xenojulis montillai de Beaufort, also in having a long free ventral margin to the by original designation, = X. margari preopercle (very restricted on Macropharyn taceus (Macleay)] godon), a more elevated dorsal fin, longer pelvic fins, one less lateral-line scale, and a DIAGNOSIS: Dorsal rays IX, 11; anal rays slightly higher gill-raker count. 111,11; pectoral rays 13; lateral-line continu ous, inclined sharply downward below soft Xenojulis margaritaceus (Macleay) portion of dorsal fin, the pored scales 26; an Figures 1-4 terior lateral-line scales with 2 pores; head naked except for a few scales on each side of Platyglossus margaritaceus Macleay, 1884: nape; scales on thorax about half as large as 274 (type locality, Hood Bay, New body scales; jaws with a row of compressed Guinea) teeth which are progressively longer and more Halichoeres macleayi Jordan and Seale, pointed anteriorly, the front teeth oflowerjaw 1906: 303 [replacement name for H. mar interdigitating with upper teeth when mouth garitaceus (Macleay) due to homonymy closed; a canine tooth at corner of mouth; with H. margaritaceus (Valenciennes)] pharyngeal dentition as in Halichoeres, the Halichoeres macleayi Fowler, 1928: 342 upper pharyngeal bones with slightly enlarged (after Jordan and Seale 1906) molariform teeth medially and posteriorly, Platyglossus margaritaceus Whitley, 1939: the lower pharyngeal bone with a large 274, fig.