Abstract
TABLE 6. Recognition and identification of the early life stages (ELS) of some poorly known deep-water members of Scorpaenidae from the Western North Atlantic. ELS are expected to share some characteristics of other members of the subfamily. Characters identified are based on the descriptions of larvae or juveniles in Eschmeyer (1965, 1969), Eschmeyer & Randall (1975), Moser et al. (1977), Moser (1996), Hardy (2005), Motomura et al. (2011), and Mertzlufft (2021), and augmented by the personal observations of the senior author for Phenacoscorpius nebris and Trachyscorpia cristulata. Classification of subfamilies within Scorpaenidae follows van der Laan et al. (2023). Abbreviations: parietal spines (P), nuchal spines (N), posterior shelf of the preopercle (PPO), anal-fin origin (AFO), anal-fin base (AFB), infraorbital ridge (IO). “Shield” of pigment refers to the extent of pigmentation over the dorsolateral surface of the visceral mass in early larvae, which may be reduced or augmented with scattered blotches in larger larvae of some taxa. The parietal spines are typically two or more times longer than the nuchals, unless otherwise noted.
TaxonRelative size & length of spines (P)arietal & PPO (N)uchalOpercle spine(s)“Shield” of pigment over gutPectoral fins Contour & Pigmentation lengthSlit behind 4 th gill archOther characteristicsScorpaeninaeIdiastion kyphosP> N likelyUnknownUpper & lower marginsUnknownLongest rays near upper part of fin; tips not beyond anal spinesUnknownYesPronounced gap between PPO-1 and -2. Membrane between dorsal spines low, about 50% of each spine exposed. Tips of lower 10 pectoral-fin rays free from membrane; tips of pelvic-fin rays short of AFO.Neomerinthe spp. 1P> NPPO-1 longest; gap between PPO-1 and -2 wider than those belowUpper & lower marginsUnlikelyFan-shaped; tips not beyond midAFBUnknownYes 2Stout parietal ridge, small nuchals. IO ridge with series of 3–4 stout, laterally projecting spines. Tips of pelvic-fin rays short of AFO.Phenacoscorpius nebrisP> NTypically, PPO-1 adjacent to IO ridge longest; PPO-2 “knob-like” or absentUpper & lower marginsScattered blotches likelyMiddle rays longest; tips of longest rays perhaps to midAFB, others to about AFOFin base & inner half of rays, or some part thereofYesSeries of 5–6 stout, laterally projecting spines along IO ridge. Tips of pelvic-fin rays short of AFO. Pigment between fifth & ninth dorsal spines; fin base & inner half of dorsal & anal fins dusky. Very short lateral line.SebastolobinaeTrachyscorpia cristulataN> PPPO-1 about two times longer than PPO-2, those below progressively shorterUpper & lower marginsDusky shield, or scattered blotches likelyUpper rays longest; tips to or slightly beyond AFOFin base & inner half of rays, or some part thereofNoParietal ridge elevated, terminates in longer nuchal than parietal spine. Series of 7–8 stout, laterally projecting spines along IO ridge. High modal pectoral-fin count of 22–23 rays. Peritoneum dusky. Lateral line complete.
1 Most head spines and other structures in 18.4 mm juvenile from south-central Pacific same as those of adults per Motomura et al. (2011)
2 Applies to Atlantic species only because some Pacific species lack said character per Motomura et al. (2011)