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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Eyes placed laterally on the head are a condition shared by all Pseudopimelodidae except for juvenile and adult Lophiosilurus. Origin of pelvic fin at vertical through end of dorsal-fin base; pelvic fin reaching anal fin when adpressed. Head and body slightly pigmented with dendritic chromatophores containing dark pigment. Pectoral fin, when adpressed, reaching vertical through base of fourth ray of dorsal fin, but lophiosilurue reaching pelvic fin.
Dorsal fin well developed, positioned distinctly in front of middle of body. Conceived and designed the experiments: Dorsal fin distinct in the early stage of postflexion, and fully developed after day First ray of pectoral fin begins to differentiate on day 6, with small hooks evident along posterior margin; after day 9, hooks visible on both sides with posterior hooks larger than anterior ones Fig 4c.
On day 17 Fig 3a, 3b and 3chead longer than wide.
Generelle Morphologie der Organismen: All fin rays segmented. In the first apomorphic state, the upper and lower caudal-fin rays are approximately similar in length, and the second apomorphic state, the middle rays lophiosi,urus the upper caudal-fin lobe become elongated. However, some species of the family have an incomplete lateral line wherein the lateral-line canal does not reach the caudal-fin base.
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Relation of relative values of body depth to relative value of body width of larvae and juvenile individuals of Lophiosilurus alexandri diamonds and mean values of other species of Pseudopimelodidae squares. Tip of inner mentonian lophiosiluruss not surpassing posterior margin of eye Fig 5a.
Primordial anal fin broadly rounded, visible as thick membrane included lophiosllurus in ventral finfold. From hatching to day 2 of development. Dark dendritic chromatophores widespread on head, most concentrated on area of frontal bone; similar chromatophores concentrated on trunk beneath dorsal fin and on caudal peduncle. Multiple illustrations were made for stages that exhibited sudden changes in morphology. Anal-fin base shorter than adipose-fin base. Actinopterygii, Lophiidae and Squatina spp.
Lophiosilurus alexandri – Wikiwand
Morphometric analysis Standard length gradually increasing immediately after hatching to nine days post-hatching; relatively aelxandri from 9 to 30 days post-hatching, then increasing more sharply from 30 to 60 days Fig 7. Even though almost all species fit the variation of depth and width present in larvae and juveniles of Lophiosilurus alexandrithree species showed values outside of the aforementioned variation: From the second day of development, barbels present.
In the development of Lophiosilurus alexandrimajor transformations in external morphology were observed between larval stages and between larvae and juveniles. Homologization of caudal skeletal structures.
The only exceptions are Lophiosilurusas described above, and Cephalosilurus fowleri. Dorsal fin in front of middle of body, when lopiosilurus not reaching adipose fin. Roberts TR Unculi Horny projections arising from single cellsan adaptive feature of the epidermis of ostariophysan fishes.
The caudal llophiosilurus of the catfishes, order Siluriformes. Pectoral fin formation starting on day 7 with emergence of rays; completely developed after day Tip of outer mentonian barbel surpassing lophjosilurus of maxillary barbel. Yolk sac very large immediately after hatching Fig 1adecreasing in volume in specimens one or two days post-hatching Fig 1b.
Received Aug 7; Accepted Mar 8. Description of eggs and larvae of jack mackerel Trachurus symmetricus and distribution and abundance of larvae in and The Evolution of Ontogeny.
Large yolk sac persistent on day 4 Fig 2a and 2bmuch reduced at day 9, and completely consumed within the 13 th day of development. The skin of fully developed specimens of Lophiosilurus possesses many finger-like papillae which begin to develop as wart-like appendages in the postflexion larvae. Breeding tubercles and contact organs in fishes: Open in aleaxndri separate window.
According alsxandri Lovejoy et al. Axillary pore very difficult to visualize in larval specimens; associated gland visible by transparency of skin.
A phylogenetic analysis of the major groups of catfishes Teleostei: Initially the dorsalmost rays of the caudal-fin upper lobe are longest than the other rays.
In the early stage of postflexion, head deep, with rounded shape in lateral view; depression of head and body starting on day The largest species of the family with mm SL, Lophiosilurus alexandriexperiences impressive changes in body shape during development, becoming extremely depressed when fully developed.
Early life history stages of fishes and their characters Ontogeny and Systematics of Fishes. Notochord straight, visible as transparency for entire length.
Pseudopimelodidae are Neotropical catfishes characterized by having slightly to strongly depressed body in fully developed specimens. The interpretation of some of these characters based on their ontogeny instead of their terminal condition in fully developed specimens may add clues to the investigation of the pseudopimelodid evolution.
Skin of head with small wart-like appendages mainly on supraorbital and ventral regions. Engield, New Hampshire, U. Reevaluation of the caudal skeleton of certain actinopterygian fishes: The caudal fin in Lophiosilurus is formed and replaces part of the finfold during the postflexion stage. Axillary gland visible above base of pectoral fin. Therefore, given its large size, unique shape, and controversial phylogenetic position, L.