Lophiosilurus alexandri: MZUEL , 3, to mm SL, Estação de Piscicultura de Três Marias, CODEVASF, on the upper São Francisco. The “pacamã”, Lophiosilurus alexandri, is a particularly interesting case for addressing this problem. Lophiosilurus alexandri is the largest.
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In fully developed specimens of Lophiosilurusthe body is extremely wide and depressed [ 26 ], a condition that is unique among pseudopimelodids and therefore autapomorphic. USNMparatype, 1, Eyes small, not pigmented in newly hatched specimens, but pigmented in one day old specimens. There is no indication that this character represents a direct i. Meristic data included the number of rays of the pectoral, pelvic, dorsal and anal fins, and total preanal and postanal myomeres.
Lateral-line canal well developed to vertical through terminus of dorsal-fin base; lateral line pores evident to vertical through middle of adipose-fin base. This is an open access article distributed under the terms of the Creative Commons Attribution Licensewhich permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. USNMholotype, From the second day of development, barbels present.
Total number of visible myomeres 38 to 43 14 to 17 preanal and 23 to 26 postanal. Pectoral fin, when adpressed, reaching vertical through dorsal-fin spine, but not reaching pelvic fin.
Intestine short, anus closed. Placement of the eyes on the dorsal surface of the head is a condition unique to juvenile and adult Lophiosilurusand therefore an autapomorphy of the species.
However, some species of the family have an incomplete lateral line wherein the lateral-line canal does not reach the caudal-fin base. Mouth not formed soon after hatching; visible in subterminal position after the first day of development.
Standard length gradually increasing immediately after hatching to nine days post-hatching; relatively constant from 9 to 30 days post-hatching, then increasing more sharply from 30 to 60 days Fig 7. Primordial adipose fin persistent as part of dorsal portion of finfold, confluent with caudal fin; lophioosilurus of adipose fin evident as small notch, otherwise confluent with caudal fin.
In fact, during the development, the length of the maxillary barbel decreases compared to the length of head, showing negative allometric growth. Esqueleto caudal de peces Siluriformes y sus tendencias evolutivas.
Allometric larval growth of the bottom-dwelling catfish Lophiosilurus alexandri Steindachner, Siluriformes: This interpretation favors the hypothesis that Cruciglanis and Pseudopimelodus are sister to all other Pseudopimelodidae, both taxa having a relatively deep body compared lophiosilurjs other species of the family.
Anal-fin base becoming longer than adipose-fin base.
INPA3, Abstract Pseudopimelodidae are Neotropical catfishes characterized by having slightly to strongly depressed body in fully developed specimens. The skin of fully xlexandri specimens of Lophiosilurus possesses many finger-like papillae which begin to develop as wart-like appendages in the postflexion larvae.
On day 17 Fig 3a, 3b and 3chead longer than wide. Ontogeny, phylogeny, paleontology, and the biogenetic law. The color pattern of most species of Pseudopimelodidae is formed by dark transverse bars on the body that is somewhat triangular, wide dorsally and tapered ventrally, and dark irregular blotches on the sides of lophisilurus and body.
Primordial anal fin broadly rounded, visible as lophiosikurus membrane included within in ventral finfold. Cleithral bulge and posterior cleithral process weakly developed on day 6, and well developed by the end of postflexion stage.
Among adult pseudopimelodids, the putative plesiomorphic state, the subterminal mouth, is present only in Cruciglanis pacifici.
Dorsal region of skull with several ridges on day The extreme condition in L. Early development stages of the catfish Lophiosilurus alexandri Steindachner, Pisces: Reevaluation of the caudal lophiosiluruw of certain actinopterygian fishes: Multiple illustrations were made for stages that exhibited sudden changes in morphology.
Changes in body shape, position of mouth and eye, morphology of fins and pigmentation were observed during the development of Lophiosilurus. MCP2, Dorsal fin distinct in the early stage of postflexion, and fully developed after day The change from the first to the second apomorphic state of this character is also observed in developmental series of many species of Auchenipteridae, Heptapteridae, and Pimelodidae [ 1428 ], indicating that this may be a evolutionary change that alexandti early in the evolution of catfishes.
Pseudopimelodidae from the Sao Francisco River basin, Brazil. Adipose-fin reduced in size with shorter base, separated from caudal fin. The regression curve corresponds only to larvae and juveniles of L.
Lophiosilurus alexandri – Wikipedia
However, the lateral-line canal of the body starts to develop in young juveniles from head to rear; the lateral-line canal extends to the vertical through the terminus of the dorsal-fin base in day old specimens. Axillary gland visible above base of pectoral fin.
Inner mentonian barbel exceeds posterior margin of eye in early stage of postflexion. Universidade Federal Rural de Pernambuco. ANSP2, Changes in body shape, position of mouth and eyes, and fin morphology were observed during the development of Lophiosilurus alexandri.
Therefore, given its large size, unique shape, and controversial phylogenetic position, L. The inclusion of the width and depth mean proportions obtained from juveniles lopyiosilurus adults of other species of the family, shows a wide distribution of these species along the X axis body depthbut with a tendency to a narrower distribution on the Y axis body width.