Order AULOPIFORMES (39)—lizardfishes. Second pharyngobranchial greatly elongated posterolaterally, extending away from third pharyngobranchial, with elongated uncinate process of second epibranchial contacting third pharyngobranchial, and (as noted byJohnson, 1992) third pharyngobranchial lacking cartilaginous condyle for articulation of second epibranchial; swim bladder absent; medial processes of pelvic girdle fused. The specialization in the gill arches is apparently not known in any other teleost (Rosen, 1973a; Johnson, 1992).
The classification of the extant families of aulopiforms follows two major phy-logenetic studies, Baldwin and Johnson (1996) with the modifications of Sato and Nakabo (2002a). The major differences between these two studies is that Sato and Nakabo (2002a) i) recognized the two clades formerly in Chlorophthalmus as being unrelated to one another (Baldwin and Johnson, 1996, had not included species of the clade now recognized as Paraulopus), ii) differed in the phylogenetic position of Bathysauroides, iii) assigned family status to Bathysauroides and Bathysauropsis (Baldwin and Johnson, 1996, while placing them in separate suborders, did not assign them to any family), and iv) recognized a different sequence for the alepisauroid families. Baldwin and Johnson (1996), considered Aulopidae to be the most primitive family, while Sato and Nakabo (2002a) found that position to belong to their new family, Paraulopidae. There are many differences from Nelson (1994), where the sequence of suborders was given as Giganturoidei (position uncertain), Aulopoidei (with only the one family), Chlorophthalmoidei, and Alepisauroidei (= Synodontoidei).
A review of past classifications and phylogenetic studies is given by Baldwin and Johnson (1996). Major contributions to our present understanding of the systematics of this order leading up to the above studies in the previous 25 years were made by K. E. Hartel, G. D. Johnson, R. K. Johnson, M. Okiyama, D. E. Rosen, M. L.J. Stiassny, and K.J. Sulak.
The families Aulopidae, Chlorophthalmidae, Ipnopidae and Synodontidae are benthic. Species in the remaining nine families tend to be pelagic to bathypelagic. Many aulopiforms are synchronous hermaphrodites.
Fifteen families with 44 genera and about 236 species.
The next two listed suborders and the families Cimolichthyidae and Enchodontidae, which are placed here in the suborder Alepisauroidei following Fielitz (2004), containing marine Cretaceous fishes, were placed in the fsuborder Enchodontoidei in Nelson (1994). They are recognized here following Patterson (1993) and Fielitz (2004). Members have the maxilla as a long, narrow strut in gape (maxilla excluded from gape in the other members of this order). Goody (1969) recognized the members of this taxon in four suborders and placed them in the order Salmoniformes. Rosen (1973a) demonstrated their relationship to the alepisauroids. However, with the notable exception of the enchodontoids, their monophyly is yet to be established and relationships to living taxa are uncertain. Genera of uncertain relations include Serrilepis and Yabrudichthys (Taverne, 1985). In addition, Taverne (2004) described Nardorex
(placing it in his new family Nardorexidae) from the marine Upper Cretaceous of Italy, noting it to show some resemblance with the Eurypholidae (placed here in the family Enchodontidae). There is need to have more studies similar to that of Fielitz (2004) that also involve a broad range of extant taxa.
fSuborder Ichthyotringoidei. Monophyly of the suborder with the families is doubtful.
Ichthyotringidae (including Apateopholidae)—e.g., Apateodus and Ichthyotringa.
Dercetidae—Seven genera of Cretaceous fishes with a very long snout and elongate and shallow body: Benthesikyme, Cyranichthys, Dercetis, Dercetoides, Hastichthys, Pelargorhynchus, Rhynchodercetis, and Stratodus (Taverne, 1990; Chalifa, 1989).
Prionolepididae—One genus, Prionolepis.
fSuborder Halecoidei. One family, Halecidae, with Halec, Hemisaurida, and Phylactocephalus (Goody, 1969).
Suborder Synodontoidei. The limits and relationships of this clade were revised by Johnson et al. (1996) and Baldwin and Johnson (1996); they altered our understanding of relationships of this group in finding characters supporting synodontoids as the most primitive aulopiform and Aulopus as cladisti-cally the most primitive member of the suborder. Sato and Nakabo (2002a) supported these conclusions, but in examining species currently placed in Paulopus (but previously placed in Chlorophthalmus and not examined in the first two studies), recognized, as accepted here, Paraulopus as the most primitive aulopiform and sister to the remaining synodontoids. Four families.
Family PARAULOPIDAE (184)—cucumber fishes. Marine; tropical to temperate, ben-thic, outer continental shelf and upper continental slopes, Indian and western Pacific (southern Japan and Emperor Seamounts south to Australia and New Zealand).
Dorsal fin rays 10 or 11; anal fin rays 8-11; pectoral fin rays 13-20; pelvic fin rays 9; pored lateral line scales 40-52; vertebrae usually 39-46; in addition, Sato and Nakabo (2002a) recognized this clade based on six apomorphies, primarily characters in the branchial arches, intermuscular bones, caudal skeleton, and pelvic girdle. Maximum length 35 cm.
Sato and Nakabo (2002a) showed in a cladistic analysis that two species groups formerly recognized in Chlorophthalmus, the C. agassizi species group and the C. oblongatus species group, were unrelated, with the latter belonging to the synodontoid clade. Within the latter clade, consisting of species of Paraulopus, Sato and Nakabo (2003) recognized two species groups, the P oblongus group with seven species of small body size (up to 15 cm SL) and the P. nigripinnis group with three species endemic to southwest Australia and New Zealand of body size up to 35 cm SL.
One genus, Paraulopus, with 10 species (Sato and Nakabo, 2002a,b; 2003).
Family AULOPIDAE (185)—flagfins. Marine; tropical and subtropical waters, Atlantic (including the Mediterranean) and Pacific.
Two supramaxillae; body slender; fulcral scales on caudal peduncle; dorsal fin origin in front third of body, fin with 14-22 rays; anal fin rays 9-13; pelvic fin thoracic, nine rays; pectoral fin lateral, 11-14 rays; scales on head and body, cycloid or ctenoid; orbitosphenoid present; vertebrae 36-53.
This family was placed in monotypic suborder Aulopoidei in Nelson (1994), with the family name orthography being Aulopodidae.
Two genera, Aulopus (4) for the Atlantic species and Hime (6) for the Pacific species, with about 10 species (e.g., Parin and Kotlyar, 1989; Thompson, 1998). Baldwin and Johnson (1996) found no evidence supporting recognition of Hime as a valid genus, and in the past it was often regarded as a junior synonym of Aulopus. Its recognition here follows Thompson's (1998) study of additional characters, although he does note that further study of variation of these characters is required in order to better support this conclusion.
Family PSEUDOTRICHONOTIDAE (186)—sandiving lizardfishes. Marine; Izu Peninsula, Japan, and Saya de Malha Bank, Indian Ocean.
Body slender and cylindrical; mouth relatively small, upper jaw bordered only by premaxillaries and slightly protrusible; lateral line complete, midlateral; cycloid scales, 46-48 in lateral line; dorsal fin single, with about 33 soft rays; anal fin rays 13-15; pectoral fin with 11 rays; pelvic fin beneath origin of dorsal, with seven long rays; caudal fin with 19 principal rays; adipose fin absent; photophores absent; no swim bladder; orbitosphenoid and mesocoracoid absent; six branchiostegal rays; 23 or 24 abdominal vertebrae and 25 or 26 caudal vertebrae. Maximum length about 9 cm SL. Individuals of the one species have been observed to dive into the sand.
Previous systematic treatment of this family is given in Nelson (1994) and Johnson et al. (1996). The latter authors described the osteology of the Japanese form known from 30-50 m over sand bottom and confirm the placement of the species in the Aulopiformes. Parin (1992), in reporting one specimen from the Indian Ocean at 110 m as a new species (Pseudotrichonotus xanthotaenia), corrects in his Addendum some errors in the original description of the species. He found minor differences with the specimens from Japan, and all should probably be
regarded as conspecific, at least until more information is available showing otherwise, despite the geographic distance separating them. Probably one species, Pseudotrichonotus altivelis.
Family SYNODONTIDAE (187)—lizardfishes. Marine (rarely brackish); Atlantic, Indian, and Pacific.
Supramaxilla small (two in Saurida and one in Harpadon) or absent; bran-chiostegal rays 8-26; vertebrae 39-67; dioecious mode of reproduction.
The subfamily Bathysaurinae with Bathysaurus, formerly recognized in this family, is now placed in its own family below. Four genera with about 57 species.
Subfamily Synodontinae (lizardfishes). Scales along lateral line not enlarged; dorsal fin rays 10-15; anal fin rays 8-16; adipose fin usually present. Maximum length about 60 cm.
Two genera, Synodus (synonym Xystodus) and Trachinocephalus, with about 37 species (e.g., Waples and Randall, 1988; Russell, 1999, 2003).
Subfamily Harpadontinae (bombay ducks). Nine pelvic fin rays (eight in other members of family); dorsal and anal fin rays 9-15.
Two genera, Harpadon (shown in figure) and Saurida, with about 20 species (e.g., Okiyama, 1984; Russell, 1999, 2003). Harpadon is secondarily pelagic and has a naked head and body except for scales along the lateral line and on part of the posterior half of the body. This subfamily is Indo-Pacific; some species of Harpadon enter brackish water.
Suborder Chlorophthalmoidei. The composition of this taxon and sequence of families follows Sato and Nakabo (2002a). Five families.
Was this article helpful?