248 



ONTOGENY AND SYSTEMATICS OF FISHES-AHLSTROM SYMPOSIUM 



Table 66. Characteristics of the Scopelarchidae. Characters and character states are defined and listed below. Positive integers indicate 

 derived states, zeroes indicate primitive states, letters denote states of characters where polarity could not be determined. 



KEY: 



Character state classification and hypothesized polanty based on detailed information presented in Johnson (1974b. 1982) and Iwami and Abe (1980). Both characters (boldface, in brackets) 

 and character states (in parentheses) are numbered sequentially. 



Gross morphohgy —{\\ Luminous tissue is (0) absent. (1) present; |2| pelvic-fin insertion is (a) antenor to dorsal-fin ongin. (b) prasienor to dorsal-fin origin; |31 length of pectoral fin is (a) 

 subequal to, (b) distinctly longer than, (c) distinctly shorter than length of pelvic fin; |4| dermal pigment stnpes as equal or subequal stripes above and below lateral line are (0) absent. (2) present. 



Merislic characiers —\5\ Modal number of vertebrae. Occurs within span of (3) 40 to 44. (0) 45 to 51, (4) 54 lo 65, hypothesized character slate sequence: 3-0-4. 



Oiieologica/ characlers —\(t\ An anterovcntrally directed prong from opisthotic reaching or nearly reaching border of proolic is (0) present. (5) absent; |7| panental bones are (0) present, (6) 

 absent; |8] supraorbital bones are (0) present. (7) absent; |9| antorbital bones are (0) present. (8) absent; |10| Ethmoid process on first infraorbital bone is (a) present, (b) absent. |ll| Supramaxillary 

 bones are (0) large, one-third to one-fourth the maxillary length; (9) splinllike. less than one-ninth of maxillary length, (10) absent: hypothesized character state sequence 0-9-10, [12] Discrete 

 postenor arm of hyomandibular bone which articulates with opercle is (0) present, (11) absent, represented only by a rounded ridge. 113) Opercle— (0) subequal to or less than, (12) distinctly 

 great than— subopercle in size. 1I4| (0) basibranchial teeth present, basihyal short, (13) basibranchial teeth absent, basihyal long. |I5| Hook-like process on anterodorsal surface of urohyal is (0) 

 absent. (14) present, |16| (0) suspensory phar>ngobranchial (PBl) present, uncinate process (UP) of first epibranchial (EBl) and second pharyngobrancial (PB2) connected by a ligament; (15) 

 FBI lacking, support of EBl near proximal end of PB2 — UP of EBl and PB2 connected by a ligament; (16) PBl lacking, support of EBI near middle of PB2. no UP. (17) PBl lacking, support 

 of EBl at point of articulation between PB2 and EB2. no UP. Hypothesized character state sequence: 0-15-16-17 



Developmental characiers — |I7| Dermal pigmentation as defined in text is (a) present, (b) absent, [181 Adipose fin (0) remains elongate (extending antenad to over antenor anal-fin base) 

 throughout transformation penod, (18) is reabsorbed early in transformation, exhibiting adult proportions in specimens 20 to 22 mm SL and larger, II9| Head length in larvae (=28 mm SL) (0) 

 not exceeding 30% SL. (19) exceeding 30% SL. |20| Pectoral fin (0) not precocious, all other fins with completely differentiated rays pnor to ossification of ventralmost rays {at least) of pectoral 

 fin, (20) precocious, all rays completely differentiated pnor to formation of complete complement of rays of all other fins (except caudal fin), (211 Pelvic fin buds (a) form midlaterally, well above 

 level of intestine, (b) form ventrolaterally, at or below level of intestine, |221 Number of pentoncal pigment sections in larvae (2 1 ) = 0. (0) = I , (22) = 3, the postenor paired sections appeanng 

 much later in development than the single antenor section, and appeanng entirely antenor to the pelvic-fin bases. (23) = 3. the postenor paired sections appeanng much later in development 

 than the single antenor section, and appeanng over the pelvic-fin bases. (24) = 3. the postenor paired sections app)eanng in near synchrony with the single antenor section and appeanng entirely 

 posterior to the pelvic-fin bases. Hypothesized character state sequence: 21 - - 22 - 23 - 24, |23| Other pigment spots or areas (as defined in text) are (0) present. (25) absent, |24| 

 Transformation is (26) gradual, onset at 12-14 mm SL or smaller, completion at 30-35 mm SL or smaller. (0) gradual, onset at 16-22 mm SL or larger, completion at 40-60 mm SL (most 

 species, R alaius is extreme with onset at 9-10 mm SL and not yet complete in 6 (39,9-80. 1 mm SL) juveniles examined by Johnson { 1 974b)], (27) abrupt; onset at 49 6-89 I mm SL or larger, 

 completion at 68.3-98.6 mm SL or larger (size for both onset and completion of metamorphosis vanes among the 5 species of Benlhalhella). Hypothesized character states sequence: 26 - - 

 27. 



subopercle 13 (12) and two reductive characters 7 (6) and 1 1 

 (9). Further linking S. danae 'wiih Scopelarchus is a unique early 

 restriction of the base of the dorsal adipose fin 18 (18). I am 

 convinced that the characters previously detailed warrant ge- 

 neric level recognition for the group of 4 species assigned to 

 Scopelarchus. Thus Scopelarchoides (type-species S. nicholsi) 

 should be restricted to S. nicholsi and S. danae. 



This leaves the three species currently assigned to Scopelar- 

 choides, viz. S. signifer, S. climax, and 5". kreffti. These three 

 share no known derived character unique to just this group. 



They share a single presumably derivative character— loss of 

 basibranchial teeth, extension of length of basihyal tooth row 

 14 (13)— with Benlhalhella but as noted by Johnson (1974b: 

 204) this may represent adult retention of a larval character 

 state common to all scopelarchids. Scopelarchoides kreffti. a 

 subtropical convergence species, shares with Benlhalhella an 

 increase in the number of vertebrae 5 (4) and probably shares 

 with B. infans the presence of luminous tissue 1(1). Most os- 

 teological characters arc unknown for 5. climax and S. kreffti 

 (as a resuU of paucity of available material) and the larvae of 



