| Diagnosis: |
Dorsal spines (total): 16-16; Dorsal soft rays (total): 11-12; Anal spines: 3-3; Anal soft rays: 8-9. Diagnosis: A smallish laterally spotted haplochromine distinguished by the following characters in combination: suprapectoral spot mostly below upper lateral line but extending above it by about one-half to one scale; 10-11 gill rakers on lower outer arch; and lower pharyngeal bone with posteromedian teeth molariform with stout shafts and rounded crowns (Ref. 119408). The placement of the suprapectoral spot overlapping the upper lateral line distinguishes Otopharynx aletes from O. brooksi, O. lithobates, and O. ovatus, al of which have the suprapectoral spot entirely below and usually separated from the upper lateral line; Otopharynx aletes has more scales in the lateral line, 34-36, than 31-33 in O. brooksi, 31-33 in O. spelaeotes, 29-31 in O. antron, 30-32 in O. tetraspilus, and 30-33 in O. tetrastigma, but fewer than O. decorus, which has 36-38 and which also has 13-14 soft dorsal rays vs. 11-12 in O. aletes; with 10-11 gill rakers on the lower outer arch, O. aletes is readily separated from O. auromarginatus with 14-18; its longer caudal peduncle, 1.6-2.0 times as long as deep, and shallowly emarginate caudal fin distinguish O. aletes from O. selenurus, with caudal peduncle 1.0-1.5 times as long as deep, caudal fin crescentically emarginate; the bicuspid outer jaw teeth, molariform pharyngeal teeth, and seven to eight subdorsal bars differentiate O. aletes from O. speciosus, with outer jaw teeth unicuspid, pharyngeal teeth all small, bicuspid; about four subdorsal bars; the presence of seven to eight vertical bars below dorsal-fin base separates O. aletes from O. argyrosoma, which lacks vertical bars; the unthickened, nonlobate lips differentiate O. aletes from O. pachycheilus, which has lips thickened, medially lobate; the 16 dorsal-fin spines, absence of distinct equidistant dorsal midline spots, and offshore habitat on sand or soft bottom distinguish O. aletes from O. heterodon, which has 17-18 dorsal-fin spines, about five distinct dorsal midline spots, and inhabits rocky shores (Ref. 119408). Trematocranus brevirostris somewhat resembles O. aletes, but in O. aletes the suprapectoral spot is largely below the upper lateral line but extends above it by about one-half to one scale vs. placed more above than below the upper lateral line, at least in the lectotype; the cephalic lateral-line system is not enlarged vs. pores and canals inflated; the dorsal fin has 11-12 segmented rays vs. 9; there are 54-67 outer upper-jaw teeth vs. about 43; the posteromedian teeth on the lower pharyngeal bone are molariform with stout shafts and rounded crowns vs. slightly enlarged but cuspidate; and the caudal peduncle length/depth ratio is 1.6-2.0 vs. 1.2-1.4 (Ref. 119408). Compared to Otopharynx panniculus, O. aletes has more scales in the lateral line, 34-36 vs. 31-33; and a heavier lower pharyngeal jaw bone and dentition, including enlarged, molarized teeth posteromedially vs. small, laterally compressed, bicuspid teeth; posterior horns thickened vs. slender; and anterior blade shorter, deeper vs. longer, more shallow (Ref. 119408). Compared to O. peridodeka, O. aletes has the hemijaws in ventral view divergent caudally and distant from each other vs. approximated, convergent; and a heavier lower pharyngeal bone, with horns thicker, posteromedian teeth enlarged, and molarized with nearly hemispherical crowns vs. more lightly built, horns narrower, posteromedian teeth somewhat enlarged but more laterally compressed, cuspidate (Ref. 119408).
Description: Deep bodied, body depth 32.1-36.9% of standard length (Ref. 119408). Dorsal profile straight or slightly convex from snout tip to above center or rear of orbit, about evenly rounded from there to end of dorsal-fin base, more convex than ventral profile; premaxillary pedicels slightly prominent, their angle 42-53°, interorbital angle 34-47°, nuchal angle 16-25°; ventral profile slightly convex from lower-jaw tip to posterior margin of branchiostegal membrane; hinge of lower jaw often protruding (Ref. 119408). Jaws equal anteriorly or lower projecting very slightly, lower jaw not dorsoventrally flattened; lips neither thickened nor lobate; gape inclination 22-38°; lower-jaw length-width ratio intermediate, the hemijaws diverging posteriorly; lower-jaw underside angle 27-40°; snout acuteness 73-85°; eyes large, nearly round, orbit length 34.1-37.4% of head length, slightly longer than tall; pupil rounded both anteriorly and posteriorly; eye not reaching dorsal head profile (Ref. 119408). Caudal peduncle 17.6-20.8% of standard length, its length 1.6-2.0 times its depth (Ref. 119408). Dorsal fin and, especially, anal fin with pungent spines, both fins with soft portion acute posteriorly; caudal fin emarginate, lobes equal in length; pectoral fin long, 32.3-39.3% of standard length, reaching level of base of third anal-fin spine or even that of third anal soft ray; pelvic fins pointed (Ref. 119408). Dental arcade of each jaw rounded; upper jaw with 54-69 teeth in outer row; outer upper-jaw teeth small, closely spaced, with crowns slightly recurved; anterior 11-15 on each side unequally bicuspid, implanted with shafts angled slightly outward; an accasional unequally tricuspid tooth among the bicuspids, posterolateral and posterior teeth unicuspid; about six most posterior unicuspids larger than midlateral unicuspids; lower jaw rather shallow but not flattened; lower-jaw dentition of haplochromis type, the outer row with 44-65 teeth; inner teeth of both jaws in two or three rows, unicuspid, crowns recurved slightly (Ref. 119408). Lower pharyngeal bone subtriangular, rather heavily built; posterior contour variably concave medially a slight to moderate amount, with short robust horns, that widen distally; median suture varying from straight or slightly sinuous to meandering posteriorly with several short interdigitations; keel slightly descending, deep, but with length greater than depth; strongly convex below; bone robust in posterior view; lateral edges of dentigerous surface with a row of regularly and closely spaced, small acutely cuspidate teeth; posterior half of median dentigerous area with a roughly circular patch of enlarged, molariform teeth with domelike crowns, tooth size and degree of molarization decreasing beyond edges of circular area; teeth in anterior half of 2-4 median columns bicuspid and smaller than posterior molars, but clearly larger than lateral teeth; posterolateral areas with teeth small, closely spaced, laterally compressed, bicuspid; teeth in posterior row 33-41; in each median column 7-11; in each oblique row 5-7 (Ref. 119408). Lacrimal bone bearing four neuromasts and five lateral-line pores; lacrimal notch distinct (Ref. 119408). Gill rakers 10-11 on lower limb of outer arch; unbranched, subequal in length; some specimens lacking any melanophores, others having several melanophores on each lower-limb raker (Ref. 119408). Scales ctenoid; 34-36 in lateral line; lateral line discontinuous; upper section with downward kink one to two scales long, or kink lacking; squamation extending onto caudal fin between fin rays, to near tips of upper and lower lobes and on basal one-fourth to two-fifths along middle rays; soft dorsal and anal fins with a few small scales between bases of some rays; size transition gradual from larger abdominal to smaller thoracic scales (Ref. 119408).
Colouration: Colouration in life not known (Ref. 119408). Colouration in preservative: head and flanks medium brown, dorsal head surface and nuchal region a little darker; no silvery or whitish areas on chest or belly; an opercular spot; an indefinite darker area between eye and rear of upper jaw, broadest along orbital margin; no distinct head stripes; branchiostegal membrane dark brown in males; seven or eight narrow dark vertical bars below dorsal-fin base; three lateral spots present but usually faint, suprapectoral spot larger and usually darker than supraanal and precaudal spots; suprapectoral spot trapezoidal with anterior edge sloping up and forward, this spot overlapping subdorsal bars 3 and 4, covering six to seven consecutive upper lateral-line scales, and extending vertically from just above lateral midline to one-half scale above upper lateral-line canals; supraanal spot on last subdorsal bar between upper and lower lateral lines, when visible a little wider and darker than the bar; precaudal spot at end of caudal peduncle; no dorsal midline spots; dorsal fin with pale lappets, remainder of fin brownish with thinly scattered melanophores; vague maculae in soft part; anal fin brownish, paler basally, without evident eggspots in available specimens; caudal fin brown, darkest on upper and lower leading edges; no obvious markings; pelvics brown on leading half of fin, unmarked on remainder; pectorals without melanophores (Ref. 119408). |