Japan. J. Ichthyol. 42(1): 1-6, 1995 魚 類 学 雑 誌 42(1): 1-6, 1 9 9 5 A New Species of Choridactylus (Pisces: Scorpaenoidei) from Southern Oman Stuart G. Poss1 and Jonathan K.L. Mee2 Gulf Coast Research Laboratory, P.O. Box 7000, Ocean Springs, MS 39566, U S A Oregon State University, Department of Fisheries and Wildlife, Hatfield Marine Science Cent e r , Marine Science Drive, Newport, Oregon 97365, U S A (Received August 29, 1994; in revised form January 13, 1995; accepted January 14, 199 5 ) Abstract Choridactylus lineatus is described as new to science based on two specimens collected in a trawl off the south coast of Oman near Salalah. Possessing conspicuous narrow, horizontal white lines t h a t run nearly the length of its body, it differs from the two other species of Choridactylus Richardson , C. multibarbus (Richardson, 1848), which ranges from the Indo-West Pacific to India , and C. natalen s i s (Gilchrist, 1902), which occurs off southeastern Africa. C. lineatus also differs from the other species in lacking distinct markings on the medial surface of the pectoral fin. Like its stonefish relatives , C. linea t u s has well-developed skin glands. Like other species of the Choridactylinae (Choridactylus and Inimicu s ) , these glands arranged sequentially and best developed dorsal of the lateral line. A key to the species of Choridactylus is provide d . In 1848 John Richardson described the genus of Eschmeyer et al. (1979), as supplemented by Poss Choridactylus from a specimen of a single species, (1982). Counts for the holotype are listed first, Choridactylus multibarbus, reported from the "Seas followed in parentheses by those of the paratype. of China." This species has been subsequently re- When counts are the same only one is listed. Mea- ported from India and adjoing seas, the Red Sea, the surements in mm for the holotype preceed those of Persian Gulf, the Philippines, the South China Sea the paratype, with the percentage standard length and the Gulf of Thailand. The genus was reviewed given in parentheses. Institutional codes follow by Eschmeyer et al. (1979), who provided references those given in Leviton et al., 1985. to earlier work and summarized its distribution. In 1902, Gilchrist described Choridactylodes natalensis from southern Africa, which was subsequently Key to the Species of Choridactylus placed into Choridactylus by Barnard (1927). This species has been reported subsequently from Durban 1a. Body strikingly covered by numerous white Bay to southern Mozambique (Eschmeyer et al., wavy lines; coloration of medial surface of pec- 1979). toral fin almost uniform dark brown or black(cid:129)c(cid:129)c This paper describes a third species, collected by Choridactylus lineatus sp. nov. the junior author aboard the R/V Rastrelliger, an b. Body with spots, specks or irregular marks, 1but FAO vessel conducting survey work for the govern- without distinct wavy longitudinal white lines; ment of Oman off the south coast of Oman near medial surface of pectoral fin with either light Salalah. The new species shares features with both brown between fin rays and with dark streaks C. multibarbus and C. natalensis, but is clearly dis- over fin rays or with numerous white spots on a tinct from either. Its capture brings the number of black background(cid:129)c(cid:129)c2 scorpaenoids known from the Western Indian Ocean 2a. Medial surface of pectoral fin with numerous to 70, including 11 from Oman. bright white spots on a black background; dor- salmost pectoral rays never filamentous; pelvic fin similarly colored; dorsal fin with 13-15 Methods spines, but usually 13(cid:129)c(cid:129)cC. multibarbus 2b. Medial surface of pectoral fin light brown be- Methods of counting and measuring follow those tween fin rays and with dark streaks over fin 1 S.G. Poss & J.K.L. Mee Fig. 1. Holotype of Choridactylus lineatus in lateral view (CAS 73230, 187.7mm SL). la; first small, near base of second, pointing post- rays; dorsalmost pectoral rays filamentous in eroventrally; second long, about 4 times length of specimens greater than about (50mm SL); first, pungent, pointing posteriorly and somewhat pelvic fin without spots; dorsal fin with 14 or 15 ventrally, reaching to level of posterior margin of spines, usually 14(cid:129)c(cid:129)cC. natalensis pupil; a short spine or point on lateral face of bone at base of second spine pointing laterally. IO2 without Choridactylus lineatus sp. nov. spines. IO3 without spines, relatively broad post- eriorly. IO4 an elongate thin tube. Nasal spine (Figs. 1, 2) absent, but ascending process of premaxilla promi- Holotype. CAS 73230 (187.7mm SL) Arabian Sea, nent. Interorbital broad, with widely spaced ridges off south coast of Oman off Salalah (16(cid:129)‹52'N, 54(cid:129)‹09'E- that separate a broad deep groove between sides of 16(cid:129)‹51'N, 54(cid:129)‹11'E) 41-42m, trawl 93, FAO It/V Rastrelli- interorbit. Interorbital ridges diverge slightly post- ger, J.K.L. Mee, daylight hours, 18 Feb. 1990. eriorly and merge with pronounced transverse ridge Paratype. BPBM 34505 (179.9mm SL), same data as that extends across posterior end of the interorbit at holotype. the anterior margin of the occiput. Preocular spine stout. Supraocular spine with a small point preceed- Description. Dorsal fin-rays XIV, 9 1/2 (XIV, ing it. Postocular spine better developed than supra- 8 1/2). Anal fin-rays II, 8 1/2. Pectoral fin-rays 12, ocular spine. Each spine on dorsal margin of the 2-5 or 6 (counted from above) branched. Lateral orbit is connected to interorbital ridge by ridges that line with about 13 (14) scales, with last scale extend- extend laterally from rear of orbit. Tympanic spine ing over base of caudal fin. Gill rakers of first arch absent. Coronal spines absent. Sphenotic spine 2-4 in upper arch +1 at middle of arch +11 or 12 in forms a prominent ridge but not ending in a well- lower arch. Caudal fin with 5:6 branched rays defined spine. No spines along postocular margin (ventral: dorsal), 7:7 segmented rays, and 1:2 un- between postocular and sphenotic spine. Pterotic segmented, procurrent rays. Vertebrae 26, with 10 with a slightly curved ridge that does not end in a precaudal and 16 caudal centra. well-defined spine. Parietal spines blade-like along Head small to moderate size (29-30% SL). Infra- anterior margin but fusing into base of nuchal spines orbital 1(IO1) with 2 spines that extend over maxil- 2 New Scorpaenoid Fig. 2. Transverse sections of gland observed in skin dorsal to lateral line and ventral to dorsal fin-spines 8-11 of BPBM 34505. A) Anteriorly near apex of excretory duct (ed) surrounded by connective tissue (ct) (bar=200ƒÊm); B) at level of excretory duct near mid-point of gland (bar=200ƒÊm); C) and D) at duct near its posterior terminus (note vestigial scale (vs); bar=200ƒÊm); E) and F) holocrine gland cells (hgc) near terminus of duct (note acinii [arrows]; bar=50ƒÊm). without forming well-defined points. Nuchal spines posterior margin of operculum; second spine about stout, not particularly pungent. Occiput naked , with 1/5 length of first, pungent; third a small point , deep transverse channel between transverse ridges at smaller than fourth; fifth a barely perceptible point level of postorbital spines and parietal spines . No near mandible. No supplemental preopercular spine . scales on head. Dorsal posttemporal spine large Operculum relatively small, with ridges that end prominent, somewhat more pungent than neighbor- in slight points, the uppermost better developed . ing spines; ventral posttemporal spine small . Supra- Maxilla extends to level about middle of pupil , cleithral spine absent. Cleithral spine large, thick, without scales. Fringed, fleshy, relatively elongate well developed. Posterior margin of preoperculum cirri on mandible. Small slit present posterior to last with 5 spines, the dorsalmost much larger than rest, hemibranch. extending posteriorly and slightly dorsally , nearly to Body without scales, except for lateral line . Later- 3 S.G. Poss & J.K.L. Mee al line scales weakly ossified and appearing only as Head length 54.5 (29), 53.6 (30); snout 18.3 (10), thin tubes. Cirri absent on body. Body with 11 to 13 17.9 (10); orbit diameter 12.7 (7), 12.7 (7); least well-developed venom glands sequentially arranged width of interorbit 17.8 (9), 16.8 (9); upper jaw above lateral line, each with a prominent extcretory length 18.5 (10), 17.7 (10); postorbit 30.2 (16), 28.1 duct (Fig. 2); 0-3 less-developed glands dorsal to (16); body depth at level of pelvic insertion 59.8 base of anal fin. Swimbladder absent. (32), 52.9 (29); predorsal 37.8 (20), 39.8 (22); anal Dorsal fin originates immediately behind parietal fin 101.1 (54), 82.6 (46); caudal fin 60.1 (32), 64.7 spines; spines 3-4 longest, with anteriormost spines (36); pectoral fin 66.2 (35), 63.1 (35); pelvic fin 69.9 more curved than those posteriorly; all soft rays (37), 64.2 (36); first dorsal spine 28.6 (16), 29.1 branched. Anal fin with 2 spines, second longer than (15); second dorsal spine 49.8 (27), 52.6 (29); third first; all soft rays branched. Pectoral fin with lower- dorsal spine 51.6 (27), 63.6 (35); fourth dorsal spine most 3 rays free from rest of fin, with thickend 48.5 (26), 60.6 (34); fifth dorsal spine 48.0 (26), 45.3 epidermial cuticle distally; middle fin rays longest, (25); penultimate dorsal spine 28.7 (15), 19.0 (11); extending posteriorly past base of second anal spine. last dorsal spine 14.9 (16), 19.8 (11); first anal spine Caudal fin oblong, rounded. 14.9 (8), 11.8 (7); second anal spine 20.9 (8), 16.1 Caudal skeleton with last haemal spine ankylosed (7); third anal ray 33.0 (15), 26.8 (18); width be- to second preural centrum (to third in paratype), not tween interorbital ridge 8.4 (9), 1.8 (9); caudal supporting procurrent caudal fin-rays; parhypural peduncle 15.8 (10), 17.6 (8); snout to base of second ankylosed to second preural centrum and weakly dorsal spine 43.7 (24), 43.0 (23); snout to base of ankylosed to compound urostylar centrum, but free third dorsal spine 50.5 (27), 50.6 (28); snout to base of hypurals, typically supporting 1 unsegmented ray of fourth dorsal spine 58.9 (31), 58.2 (32); snout to ventral to lowermost branched ray; hypurals 1 and 2, base of fifth dorsal spine 65.2 (35), 65.1 (36); width usually supporting 5 branched rays, ankylosed to of first dorsal spine at midlength 2.5 (1.0), 1.8 (1.0); urostylar centrum and hypural 3; hypurals 3 and 4 depth of interorbit 2.5 (1.3), 4.5 (2.5); incision of fin fused, firmly ankylosed to urostylar centrum; sup- membrane at fourth dorsal spine from tip to mem- brane 27.9 (15), 30.4 (17); snout to pelvic insertion porting 6 branched rays; hypural 5 autogenous, sup- porting 1 segmented but unbranched ray; 3 epurals, 43.3 (23), 45.6 (25); opercular tip to dorsal fin 25.2 none supporting procurrent rays; uroneural long, (13), 24.3 (13); uppermost preopercular spine length broad; neural spine of preural centrum. 15.0 (8), 14.4 (8); base of first dorsal spine to base of Head and body brown. Head darker dorsally, fifth dorsal spine 29.9 (16), 30.1 (17); base of fifth lighter ventrally. Small white vermiculations, most dorsal spine to pelvic insertion 62.5 (33), 55.8 (31); notable over operculum; forming minute white first dorsal spine base to pelvic insertion 50.3 (27), specks ventrally. Distinct long, narrow white lines 50.8 (28); fifth dorsal spine base to base of last dorsal on side of body, extending onto caudal fin distally, spine 64.0 (34), 68.2 (38); base of last dorsal spine to and extending onto base of dorsal fin; lines run base of last dorsal ray 62.5 (33), 57.3 (32); base of almost horizontally on body and obliquely over most last dorsal ray to base of last anal ray 19.6 (10), 19.7 of dorsal fin. Lines much shorter and forming small (11); anal origin to base of last anal ray 71.9 (38), white vermiculations behind head dorsally. Flank 72.2 (40); pelvic insertion to anal origin 51.6 (28), immediately dorsal and medial to pectoral fin with 54.1 (30); first dorsal spine base to anal origin 84.7 distinct white spots. Several large black blotches or (45), 83.8 (47); base of last dorsal spine to pelvic spots on dorsum, those at base of dorsal spines 8-10 insertion 87.8 (47), 87.6 (49); base of last dorsal most prominent. Ventrum with scattered white spots spine to base of last anal ray 60.1 (47), 62.2 (35); and speckes. Dorsal fin black near tips. Anal fin base of last dorsal ray to anal origin 84.2 (44), 86.5 black. Caudal fin with two narrow pale bars, the (48); base of last dorsal spine to anal origin 51.1 second wider and more distinct than the first. Pecto- (27), 47.5 (26); base of fifth dorsal spine to anal ral fins dark, black distally, with numerous white origin 74.6 (40), 72.1 (40). specks and short white lines over base of lateral surface, but relatively uniform light brown pro- ximally, becoming darker, nearly black distally and Discussion without specks or spots on medial surface. Pelvic fins black, with a few white specks at base. Although Kaup (1858) first proposed the Chori- (cid:129)\ 4 (cid:129)\ New Scorpaenoid dactylinae as a subfamily of the Scorpaenidae, it was Choridactylus multibarbus is relatively well known Gill (1893, 1905), who first correctly identified their from the western Pacific and the northern Indian close relationships with the Synanceidae. Jordan and Ocean and is taken near shore to 40m. It reaches Starks (1904) and Matsubara (1943) concurred with the Red Sea, with records from the Gulf of Oman , this opinion, although these authors ranked these and the Persian Gulf. In contrast, Choridactylus fishes as subfamilies (Pelorinae and Synanceiinae) of natalensis occurs at greater depths (35-75m) , is the Scorpaenidae. As noted by Eschmeyer, et al . more rarely taken, and known only from Durban (1979), Choridactylus and Inimicus are similar in fin northward to southern Mozambique (Inhaca Penin- ray counts and in being largely devoid of scales and sula). Choridactylus lineatus from southern Oman form a group distinct from other scorpaenoids . comprised much less than 1% of the haul in which it However, synapomorphies have not been established was taken, with 21% of the catch by weight being that would assert their status as sister-genera distinct Cheimerius nufar, 21% Argyrops filamentosus, 16% from other synanceids and some velvetfishes, which Lethrinus nebulosus, 14% Umbrina ronchus , 7% also share these features. Choridactylines share re- Argyrops spinifer, Suffiamen fraenatus, and 3% stricted gill openings with synanceiines, bathyaplo- Plectorhinchus pictus. Some 35 other species were actine aploactinids, and minoines, as well as supra- reported in the haul, including 2 other scorpaenoids , occipitals lacking a medial crest, partially reduced or Pterois russelli and Pterois mombasae. "lunate" metapterygoid lamina , emarginate post- The new species shares a mixture of characters temporals, dorsal-most actinost ankylosed to cora- seen in its two previously described congeners and, coid, and bayonet-shaped supracleithra, which are with additional collecting, may prove intermediate in specializations that Matsubara (1943) used to sug- dorsal and anal fin-ray counts. Available compara- gest their propinquity. Although the pattern of tive materials of both C. multibarbus (ANSP 77541; variation in these features is complex and can not be BMNH uncat. [holotype]; BPBM 21081; CAS used uncritically to assert synapomorphy, to these we 16055; CAS 15067; CAS 15068; CAS 15069; CAS may add the presence of well-developed and regular- 15071; CAS 15072; CAS 31462; CAS 33951; MNHN ly arranged, acinar secretory glands with excretory 02-196; SU 14665; UMMZ 22698; UMMZ 21690; ducts to the skin surface. These glands contain UW 10164) and C. natalensis (BMNH 1901 .9.24.2; holocrine cells bearing proteinaceous product and ANSP 86316; ANSP 87807; ANSP 88020; CAS are of similar histology to those reported by Cam- 31463; RUSI 2000; RUSI 2001) show notable varia- eron and Endean (1966) in Notesthes and Cameron tion in both counts. Unlike either species, the medial and Endean (1972) in Paraploactis. Although the surface of the pectoral fin bears no longitudinal glands are probably homologous, it is unclear if the streaks. It is a relatively uniform light brown pro- well-developed excretory ducts, as well as the several ximally, becoming darker, nearly black distally, like patterns of distribution of glands over the body, have C. multibarbus. The white lines on the body break evolved more than once. Proteinaceous secretory up into small spots on the caudal fin, similar to those gland-cell clusters are observed in the skin of species found elsewhere on the body of C. multibarbus, but of Kanekonia and likely occur in other aploactinids, nowhere are these spots large. The banded skin although in velvetfishes they are more superficial , less coloration, so strikingly evident in C. lineatus, is seen well-organized, and lack well-developed excretory elsewhere only in the proximal part of the pectoral ducts. In the Choridactylinae these glands are typi- axil of Inimicus didactylus. Although the color cally sequentially arranged and best developed above pattern over the body and fins of C. multibarbus and the lateral line, but also occur ventral to it, either C. natalensis are most similar, which of the three immediately below the lateral line or just dorsal to species are most closely related remains difficult to the anal fin. Similar acinar glands are found in Erosa establish, because material of both C. natalensis and (including Dampierosa), Leptosynanceia, Synanceia, C. lineatus are limited. Pseudosynanceia, and Trachicephalus. However , in Synanceia they appear associated with "warts," that are more numerous and occur over the entire body, Acknowledgments whereas in Erosa, Leptosynanceia, Pseudosynanceia, and Trachicephalus these glands are fewer in The authors thank Thabit Zahran Alabdisalaam number, serially arranged, and typically smaller. and Mohammed Amour al-Barwani of the Oman 5 S.G. Poss & J.K.L. Mee Marine Science and Fisheries Center, and Hammed Invest. S. Afr., 2: 1-107. Soud al-Mazrouee of the Oman Aquarium, and Hilal Gill, T. 1893. Families and subfamiles of fishes. Mem. Nat. Acad. Sci., 6: 125-138. Ambusaidi for assistance in making collection of the Gill, T. 1905. Note on the genera of synanceine and new species possible. The authors also wish to thank pelorine fishes. Proc. U.S. Natl. Mus., 28(1394): 221- Dr. John E. Randall (BPBM) for the color photo- 225. graph of the species and remarks on the manuscript, Jordan, D.S. and E.C. Starks. 1904. A review of the Dr. William N. Eschmeyer (CAS) for editorial com- scorpaenoid fishes of Japan. Proc. U.S. Natl. Mus., 27 ments and assistance, and Dr. William Hawkins and (1351): 91-175, pls. 1-2. Robert Allen (GCRL) for preparation of serial sec- Kaup, J.J. 1858. Einige iiber die Acanthoipterygiens a joue tions. cuirassee Cuv. Arch. Naturgesch., 24: 329-343. Field work was made possible through the assist- Leviton, A.E., R.H. Gibbs, Jr., E. Heal and C.E. Dawson. ance of the Consortium for International Fisheries 1985. Standards in herpetology and ichthyology: Part I. and Aquaculture Development (CIFAD) project of Standard symbolic codes for institutional resource col- lections in herpetology and ichthyology. Copeia, 1985: Oregon State University and funded by the Omani- 802-832. American Joint Commission for Economic and Matsubara, K. 1943. Studies on the scorpaenoid fishes of Technical Cooperation. This work was supported in Japan (1). Trans. Sigenkagaku Kenkyusyo, 1: 1-170. part by NSF BSR 8705373 awarded to the first Poss, S.G. 1982. A new aploactinid fish of the genus author. Kanekonia from Indonesia and redescription of K. florida. Japan. J. Ichthyol., 28: 375-380. Richardson, J.R. 1848. Fishes. Pages 1-28 in A. Adams, Literature Cited ed. The zoology of the voyage of the H.M.S. "Sama- rang", under the command of Captain Sir Edward Barnard, K.H. 1927. A monograph of the marine fishes of Belcher, during the years 1843-1846. South Africa. Part II. (Teleostei-Discocephali to end. Appendix). Ann. S. Afr. Mus., 21: vii+419-1065, pls. 18-37. オマーン南部沿岸産Choridactylus(フ サカサゴ亜目)の Cameron, A.M. and R. Endean. 1966. The venom appara- 一新種 tus of the scorpionfish Notesthes robusta. Toxicon, 4: S.G. Poss・J.K.L. Mee 111. Cameron, A.M. and R. Endean. 1972. Refutation of the オマーン南部Salalah沿 岸から採集されたフサカサゴ亜目 venomous reputations of three teleost fishes. Toxicon, Choridactylus属 の一新種C. lineatusを 記載した.C. lineatusは体 10: 335-339. に顕著な白縦線を多数もち,胸 鰭の内側がほぼ暗色で目立った Eschmeyer, W.N., K.V. Rama Rao and L.E. Hallacher. 斑紋がないことで同属のC. multibarbusとC. natalensisから区別 1979. Fishes of the scorpionfish subfamily Choridactyl- される.C. lineatusは類縁の他種と同様に体の側線の背方に皮膚 inae from the Western Pacific and Indian Ocean. Proc. 腺が列をなして存在する.C. lineatusはChoridacgylus属 の第3 California Acad. Sci., 41: 475-500. 番目の種である. Gilchrist, J.D.F. 1902. South African Fishes. Mar. ― 6 ―