Clupeiformes

• Main Author: Arratia, Gloria
• Format: Text
• Language: unknown
• Published: Zenodo 2018
• Subjects: Biodiversity; Taxonomy; Argentina; Lundberg; Myers; Noire; Antarc*; antarcticus; Salvelinus alpinus
• Online Access: https://dx.doi.org/10.5281/zenodo.3716908; https://zenodo.org/record/3716908

In comparison to clupeiforms and ostariophysans, the Alepocephali comprise a small group of 137 species, 32 genera, three families and one order, all living in marine waters ( Nelson et al. , 2016). Most species of the assemblage inhabit meso- to bathypelagic environments ( Nelson et al. , 2016). Early taxonomic studies associated alepocephaliforms with clupeiforms ( e.g ., Berg, 1937, 1958; Gosline, 1960) and other primitive teleosts on the basis of common similarities, the traditional approach of the time. However, this can be misleading without completely understanding the or- der Clupeiformes as defined by Berg, which included not only the suborders Clupeoidei and Alepocephaloidei, but also several other clades, such as †Lycopteroidei, Chanoidei, Phractolaemoidei, and Salmonoidei. During the last 50 years, alepocephaliforms have been traditionally included within the Euteleostei, closer to the salmoniforms ( Greenwood et al. , 1966; Markle, 1976) or specifically within the Argentinoidei ( Greenwood, Rosen, 1971; Lauder, Liem, 1983; Begle, 1992; Johnson, Patterson, 1996; Diogo, 2008; Wiley, Johnson, 2010). The inclusion of alepocephalids within the argentinoids is based on the presence of a crumenal organ, the descended position of the distal part of the two to four epineurals, and caudal median cartilages supporting the lowermost ray of the upper caudal lobe ( Johnson, Patterson, 1996). Although those features are present in alepocephalids and argentinoids, under the new taxonomic interpretations given by molecular studies, they need further revisions. For instance: 1. A crumenal organ is a specialization of alepocephaliforms and argentinoids. It is a posterior branchial structure that was referred to as an epibranchial organ until Greenwood, Rosen (1971) named it "crumenal organ". The main distinction between the crumenal organ and the epibranchial organ is the presence of a distinct accessory cartilage that may have arisen by segmentation from the posterior articular surface of ceratobranchial 5 in alepocephalids and argentinoids ( Nelson, 1967; Greenwood, Rosen, 1971) and in Denticeps ( de Pinna, Di Dario, 2010). Thus, the finding of this accessory cartilage in Denticeps opened the necessity for extensive comparative studies in various teleosts. 2. The third feature proposed as shared by argentinoids and alepocephalids, the caudal median cartilages supporting the lowermost ray of the upper caudal lobe ( Johnson, Patterson, 1996) is controversial due to its variability. The caudal medial cartilages (mc) are commonly associated with the middle principal caudal rays (PR) in argentinoids (mc versus PR10 and 11) and not with the lowermost ray of the upper caudal lobe. The condition as shown in Fig. 7 for Argentina is also found in alepocephalids (see below, the section on Analysis of characters), salmonids ( Fujita, 1990; Arratia, Schultze, 1992), and other euteleosts ( Fujita, 1990). 3. The caudal skeleton is a complex structure in need of further investigation in alepocephaliforms (see below, Analysis of characters) and in argentinoids. Unlike most other euteleosts (and also in alepocephaliforms), argentinoids have one vertebral centrum bearing the parhypural and hypurals 1 and 2, a centrum that was interpreted as formed by preural centrum 1 plus ural centrum 1 [of the diural terminology] by Patterson (1970:figs. 38, 40] in Argentina sialis and preural centrum 1 plus ural centrum 1 plus uroneural 1 in Bathylagus antarcticus . However, it is unknown how many vertebral centra form this centrum that I interpret, in a preliminary way, as compound (CC in Fig. 7), but noting that its origin and composition is still unknown (currently under study by GA based on its ontogenetic series). A similar structure has been interpreted as a compound centrum in adult engraulids, e.g ., Engraulis and Coilia, where the centrum includes preural centrum 1 plus ural centra 2 and 3+4 [of the polyural terminology] ( Schultze, Arratia, 2013:figs. 18, 19A-D), and in ostariophysans ( e.g., Monod, 1968; Lundberg, Baskin, 1969; Fink, Fink, 1981; Schultze, Arratia, 1989, 2013; Fujita, 1990). However, it is unknown whether the structure interpreted as a compound centrum in ostariophysans forms the same way in different ostariophysan subgroups (see Schultze, Arratia, 2013; Wiley et al. , 2015). The fossil ostariophysan † Tischlingerichthys also has a long vertebral centrum bearing the parhypural and hypurals 1 and 2 ( Arratia, 1997:fig. 67). Consequently, argentinoids differ from many other euteleost clades, and also from alepocephaliforms, in the presence of a possible compound vertebral centrum that articulates with the parhypural and hypurals 1 and 2, ventrally. 4. The most anterior uroneural or modified uroneural or stegural with an antero-dorsal membranous outgrowth is interpreted as a euteleostean synapomorphy, but its absence in argentinoids is considered to be secondary by parsimony optimization ( Wiley, Johnson, 2010). The element interpre- ted as the most anterior uroneural in argentinoids and alepocephaliforms is different in both groups. The most anterior uroneural has a complex structure in argentinoids. It was identified as uroneural 1 by Patterson (1970:fig. 37), Gre- enwood, Rosen (1971:figs. 12, 14), and Fujita (1990:figs. 56-59). According to my studies, the first and enlarged uro- neural bearing an expanded membranous outgrowth is an autogenous element lying on the dorsal surface of the compound centrum in juvenile and sub-adult specimens of Argentina sialis and has an overall resemblance to the stegural of salmonids (see Arratia, Schultze, 1992; Grünbaum, Cloutier, 2010) and other euteleosts. However, the antero-lateral base of this element fuses to the dorso-lateral surface of the centrum in larger specimens, resembling a pleurostyle ( Fig. 7a, b). Consequently, this element differs from the eu- teleostean stegural (that is always an autogenous element; Arratia, Schultze, 1992; Grünbaum, Cloutier, 2010), but it also differs from the pleurostyle present in ostariophysans and clupeiforms, except for Denticeps (for information on the pleurostyle see below, section on Analysis of characters). Thus, I term this element a "pseudopleurostyle" to note its different formation than that of the pleurostyle and stegural. Summarizing, there are disagreements concerning the inter- pretations of alepocephaliforms as argentinoids and also of alepocephaliforms as salmoniforms based on morphological characters. These older interpretations based on morphological evidence ( e.g ., Greenwood et al. , 1966; Greenwood, Rosen, 1971; Markle, 1976; Lauder, Liem, 1983; Begle, 1992; Johnson, Patterson, 1996; Diogo, 2008; Wiley, Johnson, 2010) have been challenged by molecular evidence, which supports the inclusion of the alepocephaliforms within the Otomorpha (see Fig. 2b, c), specifically as sister to the Os- tariophysi (Betancur-R et al. , 2017). Lavoué et al. (2008), in turn, found the Alepocephaliformes - Ostariophysi affini- ty more likely than the Alepocephaliformes - Clupeiformes one, but no definitive conclusion was proposed. In comparison to the clupeiforms and ostariophysans, the alepocephaliform fossil record is young (Cenozoic) and sparse. It is represented by † Carpathichthys polonicus (see Fig. 8) from the Miocene-Oligocene, about 30 to 23 Ma, of Carpathians (Jerzmanska, 1979) and alepocephaliform otoliths of the Mediterranean Basin, Quaternary of Italy ( Girone, 2003; Girone et al. , 2006). : Published as part of Arratia, Gloria, 2018, Otomorphs (= otocephalans or ostarioclupeomorphs) revisited, pp. 1-24 in Neotropical Ichthyology 16 (3) on pages 6-9, DOI: 10.1590/1982-0224-20180079, http://zenodo.org/record/3710044 : {"references": ["Johnson GD, Patterson C. Relationships of lower euteleostean fishes. In: Interrelationships of fishes. Stiassny MLJ, Parenti LR, Johnson GD, editors. San Diego: Academic Press; 1996. p. 251 - 332.", "Greenwood PH, Rosen DE. Notes on the structure and relationships of the alepocephaloid fishes. American Mus Novitates. 1971; 2473: 1 - 48.", "Nelson JS, Grande T, Wilson MVH. Fishes of the World. 5 th ed. Hoboken: John Wiley & Sons; 2016.", "Berg LS. 1937. Classification of fishes, both Recent and fossil. Travaux de l'Institute de l'Academie des Sciences de l'URSS. 1937; 5: 87 - 517.", "Berg LS. 1958. System der Rezenten und fossilen Fischartigen und Fische. Berlin: Veb Deutscher Verlag der Wissenschaften. p. 1 - 310.", "Gosline WA. Contributions toward a classification of modern isospondylous fishes. Bull British Mus Natur Hist, Zool. 1960; 6: 265 - 327.", "Greenwood PH, Rosen DE, Weitzman SH, Myers GS. Phyletic studies of teleostean fishes with a provisional classification of living forms. Bull Amer Mus Natur Hist. 1966; 131 (4): 339 - 456.", "Markle DF. Preliminary studies on the systematics of deep-sea Alepocephaloidea (Pisces: Salmoniformes). PhD Thesis, Virginia: The College of William and Mary. 1976.", "Lauder GV, Liem KF. The evolution and interrelationships of the actinopterygian fishes. Bull Mus Comp Zool. 1983; 150: 95 - 197.", "Begle DP. Monophyly and relationships of the argentinoid fishes. Copeia. 1992; 1992 (2): 350 - 66.", "Diogo R. On the cephalic and pectoral girdle muscles of the deep sea fish Alepocephalus rostratus, with comments on the functional morphology and phylogenetic relationships of the Alepocephaloidei (Teleostei). Animal Biology. 2008; 58 (1): 23 - 9.", "Wiley EO, Johnson GD. A teleost classification based on a monophyletic group. In: Origin and Phylogenetic Relationships on Teleosts. Nelson JS, Schultze H-P, Wilson MVH, editors. Munchen: Verlag. Dr. F. Pfeil; 2010. p. 123 - 182.", "Nelson GJ. Epibranchial organs in lower teleostean fishes. J Zool, London. 1967; 153: 71 - 89.", "de Pinna MCC, di Dario F. The branchial arches of the primitive clupeomorpzh fish, Denticeps clupeoides, and their phylogenetic implication (Clupeiformes, Denticipitidae). In: Origin and Phylogenetic Interrelationships of Teleosts. Nelson JS, Schultze H-P, Wilson MVH, editors. Munchen: Verlag Dr. F. Pfeil; 2010. p. 251 - 268.", "Fujita K. The Caudal Skeleton of Teleostean Fishes. Tokyo: Tokai Univ. Press; 1990.", "Arratia G, Schultze H-P. Reevaluation of the caudal skeleton of certain actinopterygian fishes. III. Salmonidae. Homologization of caudal skeletal structures. J Morphol. 1992; 214 (2): 187 - 249.", "Patterson, C. Two Upper Cretaceous Salmoniform fishes from the Lebanon. Bull Brit Mus Nat Hist, Geol. 1970; 19: 205 - 96.", "Schultze H-P, Arratia G. The caudal skeleton of basal teleosts, its conventions, and some of its major evolutionary novelties in a temporal dimension. In: Mesozoic Fishes 5 - Global Diversity and Evolution. Arratia G, Schultze H-P, Wilson MVH, editors. Munchen: Verlag F. Pfeil, 2013. p. 187 - 246.", "Monod T. Le complexe urophore des poisons teleosteens. Mem Inst Fondament. Afrique Noire. 1968; 81: 1 - 705.", "Fink SV, Fink WL. Interrelationships of the Ostariophysan Fishes (Teleostei). Zool J Linnean Soc. 1981; 72 (4): 297 - 353.", "Wiley EO, Fuiten AM, Doosey MH, Lohman BK, Merkes C, Azuma M. The caudal skeleton of the zebrafish, Danio rerio, from a phylogenetic perspective: A polyural interpretation of homologous structures. Copeia. 2015; 103 (4): 740 - 750.", "Arratia G. Basal teleosts and teleostean phylogeny. Palaeo Ichthyologica. 1997; 7: 1 - 168.", "Grunbaum T, Cloutier R. Ontogeny, variation, and homology in Salvelinus alpinus caudal skeleton (Teleostei: Salmonidae). J Morphol. 2010; 271 (1): 12 - 24.", "Lavoue S, Miya M, Poulsen JY, Moller PR, Nishida M. Monophyly, phylogenetic position and interfamilial relationships of the Alepocephaliformes (Teleostei) based on whole mitogenome sequences. Mol Phyl Evol. 2008; 47 (3): 1111 - 21.", "Girone A. The Pleistocene bathyal teleostean fauna of Archi (Southern Italy): palaeoecological and palaeobiogeographic implications. Riv Italiana Paleont Strat. 2003; 109 (1): 99 - 110.", "Girone A, Nolf D, Cappetta, H. Pleistocene fish otoliths from the Mediterranean Basin: a synthesis. Geobios. 2006; 39 (5): 651 - 71."]}