Bandit Blenny

Dark spot above gill opening; dark bands on body and upper part of the head (Ref. 4404).

Oviparous, distinct pairing (Ref. 205).

Dorsal spines (total): 11 - 13; Dorsal soft rays (total): 19 - 21; Analspines: 2; Analsoft rays: 21 - 23

Oviparous. Eggs are demersal and adhesive (Ref. 205), and are attached to the substrate via a filamentous, adhesive pad or pedestal (Ref. 94114). Larvae are planktonic, often found in shallow, coastal waters (Ref. 94114).

Omobranchus banditus J. L. B. Smith

Omobranchus bandilus J. L. B. Smith, 1959:232 [Umgazi].

DESCRIPTION (see also Table 5).—Dorsal fin XI–XIII (XII in 90.7% of specimens), 19–21 = 31–33; anal fin II, 21–23; one or both anal-fin spines of males not discernible externally; segmented caudal-fin rays 13 or 15 (15 in only 1 of 55 specimens); dorsal + ventral procurrent caudal-fin rays 12–16; vertebrae 10–11 + 27–30 (rarely 27) = 38–40; epipleural ribs 15–21 (rarely 15); prenasal pores present; interorbital pores 2–3 (3 in 92.5% of specimens); circumorbital pores 7–9 (8 in 88.9% of specimens); lateral-line tubes 5–9 (rarely 9); lateral-line tubes extending posteriorly to below level of dorsal-fin spine 8–11; gill opening restricted to area dorsal to level of dorsalmost pectoral-fin ray; lower-lip flap absent (Figure 2a); circumorbital bones 5; lower jaw teeth 19–27; upper jaw teeth 17–24 (Figure 37); males over 30 mm SL with bladelike fleshy crest on top of head; crest absent in males under 30 mm SL and in all females.

COLOR PATTERN.—Males: Head: Three variable, dark bands radiating from eye on lower two-thirds of head; anterior band moderately broad at origin on anteroventral edge of orbit, flaring broadly as it crosses mouth just anterior to angle of jaws and continuing onto chin; 2nd band narrow to moderately broad, extending from midventral margin of orbit to ventral midline of head, sometimes deflected slightly posteriorly on ventral side of head; 3rd band broad, angled posteroventrally, then ventrally, from posterior margin of orbit to ventral midline of head; broad (4th) band arising approximately at midside of head in preopercular area, extending downward across branchiostegal membranes onto prepelvic area; each band meeting or confluent with corresponding band of opposite side at ventral midline of head; bands almost evenly spaced; posterior 3 bands often broken, wavy, or with branches of pigment occasionally forming irregular vermiculations on cheek. Parallel pair of narrow, irregular bands, usually angled posteroventrally from near upper end of 4th head band, extending across branchiostegal membranes to dark, vertical band on fleshy pectoral-fin base; lower band of pair may be quite short; both bands sometimes incorporated in vermiculations on cheek. Vertically oriented, moderately broad, wavy, dark line present just posterior to upper half of eye, continuing onto nape. Snout with pair of dark, often slivered, bands along anterodorsal contour of head; bands separated at dorsal midline by pale space; large specimens with snout entirely dusky. Interorbital area with 2 short, moderately broad, dark lines angled dorsoposteriorly from dorsal edge of orbit; anterior line continuing onto fleshy crest, posterior terminating on nape; posterior line appears as disconnected dorsal extension of anterior band on lower side of head. Fleshy crest with approximately 3 moderately broad, dark bands; posteriormost band usually continuous with wavy, dark line posterior to upper half of eye. Large, intensely dark spot approximately one-third to one-half size of eye on side of nape just anterior to level of 1st dorsal-fin spine; spots on both sides loosely joined across nape by narrow, dusky to dark line; anterodorsally inclined, short, narrow, dark line parallels anteroventral border of dark spot, separated from spot by slightly smaller, very pale line.

Trunk: Pale with approximately 13 evenly spaced, broad, dark bands, usually reaching from dorsal to ventral body contours, sometimes fainter ventrally and not quite reaching ventral contour; posterior 2 or 3 bands often represented only as large midlateral spots or short, broad, midlateral stripe; spaces separating bands varying from slightly broader than bands to one and one-half times as broad as bands; dorsal ends of bands sometimes expanded slightly, often with pale spot near center of expansion; dorsal ends of anterior bands sometimes deflected slightly anteriorly, ends of posterior bands deflected posteriorly; dorsal ends of bands occasionally separate from rest of bands (more often true of posterior bands); dorsal ends of posterior bands occasionally angled and connected irregularly to one another; bands often taper slightly ventrally. Some specimens with a faint, vertical, thin to moderately broad, dusky line midway in each pale interspace between body bands, most noticeable dorsally.

Pectoral Fin: Pale with fairly even spread of fine, dark specks of pigment on rays; dusky band near fin base, sometimes confined to dorsal half of fin; distal portion offindusky ventrally. Fleshy pectoral-fin base with prominent, broad, dark band extending from near lower end of gill opening to abdomen just behind pelvic-fin base; bands of opposite sides with dusky connection across ventral body midline. Second, narrow, dusky band sometimes present posteriorly on fleshy base of fin.

Pelvic Fin: Pale; dusky proximally where fin overlies ventral extension of prominent, dark band on fleshy pectoral-fin base.

Dorsal Fin: Transparent with dusky and dark markings; base of fin with large, dark blotch at dorsal end of each body band; blotches extend dorsoposteriorly on fin as broad, dusky bands; longitudinal row of approximately five dark spots present one-half to two-thirds distance up from fin base; distal area of fin usually dusky.

Anal Fin: Largely dusky, or pale with dusky bands; dark spot in membrane posterior to basal end of every third ray, usually with narrow, dusky band directed posteroventrally from each spot; distal area of fin dusky; tips of rays abruptly pale.

Caudal Fin: Pale dusky; central portion of fin base pale with 2 vertically oriented, dark spots, each with streak of dusky pigment extending slightly posteriorly; dorsal and ventral portions of fin base dusky.

Females: Similar to males except: dark markings on head, body, and fins, other than dark spot on side of nape, usually fainter; body bands noticeably fainter, particularly posteriorly; pale spots in dorsal expansions of body bands more apparent.

GEOGRAPHIC DISTRIBUTION (Figure 6).—Port Maone, Mozambique, south to Port St. Johns, South Africa. Smith (1959) and Penrith and Penrith (1972) reported that O. banditus occurred as far north as Bazaruto Island, Mozambique, but we have seen no specimens from north of Port Maone.

HABITAT.—Smith (1959) stated that O. banditus occurred in weedy and muddy areas; Penrith and Penrith (1972) reported it from rocky intertidal pools; Millard and Broekhuysen (1970) reported it from dead oyster shells in the St. Lucia estuary basin where salinities ranged from 34.4–35.2 o/oo.

COMPARISON.—Omobranchus banditus is unique in Omobranchus in lacking a lower-lip flap (Figure 2a). Its bold pattern of body bands also readily distinguishes it. Omobranchus banditus together with punctatus and mekranensis appear to form a closely related group that share the following specializations: one or both anal-fin spines of males reduced and not discernible externally, a large number of epipleural ribs, a gill opening predominantly restricted to the area dorsal to the level of the dorsalmost pectoral-fin ray, a dark spot or band present dorsally on the side just ventroanterior to the dorsal-fin origin, and a strong trend toward increased number of precaudal vertebrae to more than 10. Omobranchus woodi is also close to this group but lacks the anal-fin spine modification; however, woodi, banditus, and mekranensis share in having a fleshy crest on the head of males; the crest is lacking in punctatus. The only other species of Omobranchus in which the anal-fin spines of males are not discernible externally is steinitzi. Omobranchus steinitzi, however, has the lowest number of dorsal- and anal-fin elements and vertebrae in the genus. It also has only 14–15 epipleural ribs and is unique in the genus in lacking prenasal pores.

Aside from the lack of a lower-lip flap, presence of modified anal-fin spines, and features of its color pattern, O. banditus can be distinguished from the South African populations of those species of Omobranchus with which it appears to be broadly sympatric as follows: woodi has 0–6 (modally 5) lateral-line tubes (versus 5–9, modally 7, for banditus) and a fleshy crest on the head of females (females of banditus lack crests). Omobranchus ferox has 0–4 lateral-line tubes, which extend posteriorly no farther than to below dorsal-fin spine 7 (versus 5–9 tubes extending posteriorly to below dorsal-fin spines 8–11); O. ferox has the gill opening extending ventrally to opposite the 3rd to 6th pectoral-fin ray (versus restricted to area dorsal to dorsalmost ray); O. ferox also has 4 circumorbital bones, 10–13 epipleural ribs, and no fleshy crest on the head of either sex (versus 5 circumorbital bones, 15–21 epipleural ribs, and a fleshy crest on many males); O. punctatus lacks a fleshy crest in both sexes. Omobranchus elongatus has 0–2 lateral-line tubes, which extend posteriorly no farther than to below the level of secondary dorsal-fin spine, 11–14 epipleural ribs, gill-opening rarely restricted to area dorsal to level of dorsalmost pectoral-fin ray (usually extending ventral to first ray), and no fleshy crest on the head of either sex. Omobranchus fasciolatus has 2 interorbital pores (versus 3, rarely 2, for banditus) and usually has fewer vertebrae, dorsal-fin elements, and epipleural ribs than banditus (see Tables 5 and 8).

NOMENCLATURAL

Omobranchus banditus, the bandit blenny, is a species of combtooth blenny found in the western Indian Ocean. This species can reach a length of 6.0 centimetres (2.4 in) SL.