Dendrochirus “bellus

Ditty, James G., Malca, Estrella & Vásquez-Yeomans, Lourdes, 2024, The lionfishes: Comparative development of Pterois volitans, Dendrochirus barberi, and D. hemprichi (Scorpaeniformes: Scorpaenidae: Pteroinae) and discrimination of their early life stages from non-pteroine scorpaenid genera in the Western North Atlantic, Zootaxa 5446 (1), pp. 1-41 : 19-21

Dendrochirus “bellus ” and D. zebra

General morphology and pigmentation patterns for transforming D. “ bellus ” and D. zebra similar to that described for D. barberi and D. hemprichi . Per Kojima (2014), 9.5 mm D. “ bellus ” with large eyes, maximum body depth 38% SL; HL 36% SL. Hindgut long, relatively slender. PPO spines relatively short; pterotic and posttemporal ridges elevated posteriorly. Parietal spines anterior to nuchals, subequal in length, relatively short. Supraocular cirrus pigmented; nasal cirrus unpigmented. Dorsal and anal spines slender; first eight dorsal spines of similar length. Pectoral fins fan-shaped, rays elongate ( Fig. 6a ). Three stripes across dorsal surface of head: anteriorly between orbital margins, midway between pterotic ridges, and posteriorly near base of parietal spines. Snout with narrow swath from lower nares downward onto upper lip, and from anteroventral margin of orbit across IO1. Pigment near anterior margin and on posterolateral surface of lower lip; diffuse blotch near angle of lower jaw. Cheek with narrow diagonal swath from dorsoposterior margin of maxilla across lower part of APO, and another from posterior margin of orbit across APO; opercle with diffuse, oblong swath ( Fig. 6a ). Lateral surface of visceral mass unpigmented. Internally, dorsal surface of gas bladder lightly pigmented; hindgut with pigment midway along dorsolateral surface (partially obscured by pectorals in illustration; Fig. 6a ). Body with five partial saddles or elongate dorsolateral bands. Ventrally, “circular” pigment on abdomen near origin of pelvic fins, and diffuse blotch on pterygiophores 3–4 and terminal pterygiophore of anal-fin base; also, a diffuse vertical swath from ventral margin to lateral midline near mid-CP. Pectoral fins with diffuse blotch on shaft and membrane near insertion of rays 11–13, a series of blotches in two uneven rows (near mid-fin and toward outer margin), and pigment scattered along outer margin of fin; webbing weakly incised ( Fig. 6a ). Pelvic fins damaged, but comparably developed 9.2 mm larva with tips of middle rays beyond origin of anal-fin base ( Kojima 2014). Caudal-fin outer margin rounded.

Additional characteristics we observed in Kojima’s (2014) D. “ bellus ” include small cluster of melanophores on upper margin of orbital membrane adjacent to base of supraocular cirrus. Upper four PPO spines subequal in length, lowermost shortest; cephalosensory canal with pore above PPO-1. Parietal and nuchal spines dorsoposteriorly directed, elevation ≤15° above longitudinal axis of head. Supracleithral ridge with terminal spine. Spine on IO1–L1 slightly overlaps upper margin of maxilla. Image of larger cleared and stained larva provided by Kojima (pers. comm.) reveals low supraocular and postocular ridges with short spine along each, and short, blunt spine along posteroventral margin of IO4. First and second dorsal spines of similar length, gap between these spines narrower than subsequent spines. Length of first anal spine about two-thirds that of second; third element of anal fin ray-like, untransformed. Pelvic spine short of anus; pigment on membrane between pelvic spine and outermost ray. Clusters of melanophores near tip of first three dorsal spines, on membrane between spines 2–3 and 4–5, and at various locations along shaft or on membrane of dorsal, anal, and primary caudal rays. Series of melanophores along longitudinal axis of pectoral-fin base (not on surface of visceral mass; Kojima, pers. comm.).

Per Kojima (2014), 11.5 mm D. zebra with eyes relatively smaller than in D. “ bellus ,” maximum body depth 33% SL; HL about 34% SL; nasal and supraocular cirri relatively short. Five PPO spines; cephalosensory canal along shelf with pore between PPO-1 and -2, and -3 and -4. All fins well developed; second dorsal spine about 30% longer than first. Pectoral fins elongate, fan-shaped, webbing between rays well incised; tips of longest rays short of terminal margin of dorsal-fin base. Pectorals also have a series of diffuse, elongate blotches in uneven row across inner half of fin; outer half peppered with melanophores. Tips of longest rays of pelvic fin extend to about middle of anal-fin base; dusky, teardrop shaped blotch on inner third of shaft and membrane of outer two rays; clusters of pigment on webbing near outer margin between most rays ( Fig. 6b ). Head pigmentation similar to that of D. “ bellus ” with addition of pigment cluster on cheek adjacent to PPO-2. Five dorsolateral bands or saddles of comparable width extend onto spinous- and soft-dorsal fins; posterior pair of bands extends onto anal fin. Ventrally, abdomen with small cluster above insertion of pelvic fins (not visible in lateral view); CP with diffuse ventrolateral cluster near mid-peduncle, and roughly diamond-shaped lateral cluster in hypural area. Light cluster of pigments on dorsolateral surface of hindgut near anus partially obscured by pectoral fins in illustration. Caudal-fin outer margin rounded.

Additional characteristics we observed in Kojima’s (2014) illustration of D. zebra include small cluster of melanophores on upper margin of orbital membrane adjacent to base of supraocular cirrus as noted for D. “ bellus ”. OD nearly equal to snout length. Upper four PPO spines subequal, lowermost shortest; two small APO spines, uppermost inserted between PPO-2 and -3, lowermost overlays PPO-4. PPO spines somewhat longer in D. zebra than in D. barberi and D. “ bellus ,” but placement and orientation similar in all three. Pterotic and posttemporal ridges elevated posteriorly, pterotic ridge longer, but lower, than lower posttemporal. Lower posttemporal ridge with acute terminal margin; small spine on upper posttemporal ridge. Parietal spines anterior to nuchals, subequal in length, relatively short and dorsoposteriorly directed, elevation ≤15° above longitudinal axis of head. Supraocular and postocular spines along orbit. Nasal spine above posterior nostril; nasal and supraocular cirri of similar length, supraocular cirrus partially pigmented. Tip of IO1-L1 and IO2-L1 slightly overlap upper margin of maxilla; short spine along lower margin of IO4. Pair of acute “spine-like” structures or short ridges near margin of opercle ( Fig. 6b ). Gap between first and second dorsal spines narrower than between subsequent spines. Second dorsal spine about 25% longer than first; second anal spine about two times longer than first. Third element of anal fin ray-like, untransformed; tip of pelvic spine short of anus. Caudal fin unpigmented.

Juvenile D. zebra <15.0 mm in Matsunuma & Motomura (2019) have three, long snout barbels; nasal cirrus, very long, branched; supraocular cirrus long, unbranched; head lacks obvious dermal flaps. Upper three PPO spines exposed (lower two perhaps subdermal, or resorbed); PPO-1 longest, PPO-2 and -3 of similar length, all lack supplemental spines. Single nasal spine. These juveniles also lack sphenotic, pterotic, lower posttemporal, supracleithral, coronal, tympanic, postorbital, and opercular spines. Therefore, pterotic, lower posttemporal, and supracleithral spines in 11.5 mm transformer either subdermal, or resorbed, by 15.0 mm. Infraorbital ridges smooth, small IO1-L1; IO1-L2 flat, plate-like. Conspicuous oblique band crosses eye from base of supraocular cirrus to interopercle; otherwise, head, body, and pectoral- and pelvic fin pigmentation as described for 11.5 mm D. zebra ( Kojima 2014) . Light, downward curved swath from lateral midline to ventral margin of CP (i.e., sixth band) in a 14.0 mm larva examined by Matsunuma & Motomura (2019) corresponds to diamond-shaped, mid-lateral cluster in Fig. 6b . Numerous poorly defined, elongate blotches added to rayed portions of dorsal, anal, and caudal fins in early juveniles.

Figures

FIGURE 6. A. transforming 9.5 mm standard length (SL) Dendrochirus “bellus”; B. 11.5 mm SL D. zebra from Kojima (2014) used by permission of author and publisher.