Guide to the identification of Scorpionfish larvae (family Scorpaenidae) in the Eastern Pacific with comparative notes on species of Sebastes and Helicolenus from other oceans /

Abstract

Developmental stages of 51 species or forms of scorpionfishes are described and illustrated in this identification guide. Thirty-eight are from the eastern Pacific and represent six of the eight scorpaenid genera known from that region-Sebastes, Sebastolobus, Scorpaenodes, Scorpaena, Pontinus, and Ectreposebastes. Sebastes is the most thoroughly treated; developmental series of six species from the eastern Pacific are described and illustrated; pigment patterns of early larvae of 33 species are given and 23 of these are illustrated. Larval series of three North Atlantic species of Sebastes are described and illustrated as is a series of Sebastes from off Chile; in addition, the published information on eight northwestern Pacific species is summarized and discussed in relation to the eastern Pacific and Atlantic species. The other genera are represented by one or two species. Since larvae of the eastern Pacific species of Helicolenus were not available, a larval series of If. dactylopterus from the Atlantic are described for comparative purposes. Larvae of the eighth eastern Pacific scorpaenid genus, Trachyscorpia, are unknown. Two dichotomous keys to the eastern Pacific genera are included, one for the early larval stages up to the initiation of notochord flexion and one for postflexion larvae. In the text, a summary of the literature and definitive characters is followed by the descriptive accounts of the species. Each species account contains a literature summary, description, set of illustrations, and information on distribution and abundance. 'Trachyscorpia probably would key to couplet la and Helicolenus to 5b.

Early larvae of the swordspine rockfish (Sebastes ensifer) identified by molecular methods

“…Pectoral-fin melanophores are exclusively or most concentrated near the margin, but are more evenly distributed in the honeycomb rockfish (Sebastes umbrosus) (Moser et al, 1977;Moser, 1996b). All but the rosy rockfish (S. rosaceus) have pigment at the tip of the lower jaw (Moser et al, 1977;Matarese et al, 1989;Moser, 1996b).…”

“…Pectoral-fin melanophores are exclusively or most concentrated near the margin, but are more evenly distributed in the honeycomb rockfish (Sebastes umbrosus) (Moser et al, 1977;Moser, 1996b). All but the rosy rockfish (S. rosaceus) have pigment at the tip of the lower jaw (Moser et al, 1977;Matarese et al, 1989;Moser, 1996b). On the basis of morphological features and pigmentation early during the preflexion stage, larval S. ensifer are essentially indistinguishable from the other Sebastomus larvae, except perhaps Sebastes rosaceus and S. umbrosus.…”

“…Differences among larvae of Sebastomus species are quite small (e.g., Moser, 1996b;Rocha-Olivares, 1998;RochaOlivares et al, 2000), and currently larvae of none of these species can be reliably identified with traditional morphological and pigment characters. Complete larval development for any Sebastomus species is still unknown; to date, extrusion larvae are known for 7 of the 15 species, and some later stages are known for 4 species, including the cape redfish (S. capensis) of the Southern Hemisphere (e.g., Westrheim et al 1 ;Moser, 1967;Moser et al, 1977;Richardson and Laroche, 1979;Moser and Butler, 1987;Matarese et al, 1989;Sabatés and Olivar, 1990;Moser, 1996b;Rocha-Olivares et al, 2000). Larvae of another species, probably buccaneer rockfish (S. exsul) or spinyeye rockfish (S. spinorbis), have been described through the postflexion stage (Moser et al, 1977).…”

“…Complete larval development for any Sebastomus species is still unknown; to date, extrusion larvae are known for 7 of the 15 species, and some later stages are known for 4 species, including the cape redfish (S. capensis) of the Southern Hemisphere (e.g., Westrheim et al 1 ;Moser, 1967;Moser et al, 1977;Richardson and Laroche, 1979;Moser and Butler, 1987;Matarese et al, 1989;Sabatés and Olivar, 1990;Moser, 1996b;Rocha-Olivares et al, 2000). Larvae of another species, probably buccaneer rockfish (S. exsul) or spinyeye rockfish (S. spinorbis), have been described through the postflexion stage (Moser et al, 1977). Early development of S. ensifer is known only from newly extruded larvae (Moser, 1967) and from large, transforming larvae (≥19.8 mm standard length) and pelagic juveniles (Rocha-Olivares et al, 2000).…”

A Process for Evaluating Adverse Environmental Impacts by Cooling-Water System Entrainment at a California Power Plant

“…Larval Sebastes are very difficult to visually identify to the species level [17,18,19,20,21,22]. Perhaps 5 or 6 of the 59 rockfish species expected to occur in the vicinity of DCPP can be identified at the early larval stage to the species level [22]: aurora rockfish (S. aurora), shortbelly rockfish (S. jordani), cowcod (S. levis), blue rockfish (S. mystinus), bocaccio (S. paucispinis), and stripetail rockfish (S. saxicola).…”