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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This monotypic genus also exhibits the most alexaneri modified morphology for the family. Incipient caudal fin formed by finfold and confluent with dorsal and ventral portions of finfold; dorsal caudal-fin lobe more developed and slightly longer than ventral lobe, with 15 incipient rays visible in 4-day old specimens Fig 2a.

Inner mentonian barbel exceeds posterior margin lophiosilurks eye in early stage of postflexion. For each stage of development, specimen illustrations were made with the aid of a camera lucida coupled to a stereomicroscope.

Relative to standard length, measurements of snout length, head depth and body depth are smaller in juveniles than in larvae, but body width is larger. A third state, mouth slightly superior, is present in adult Pseudopimelodus and some Microglanis. Published online Apr Twenty-three measurements were obtained on juveniles using a digital caliper accurate to 0. Accordingly, Lophiosilurus alexandri is alexandr ideal species to observe the morphological changes during ontogeny, and to seek solid interpretations on the polarity of characters.

Morphometric variables were expressed as percentages of standard length, except for subunits of the head, expressed as percentages of head length.

Lophiosilurus alexandri – Wikipedia

ANSP2, Dorsal fin distinct in the early stage of postflexion, and fully developed after day The maxillary barbel is relatively short in Lophiosilurusfalling shy of the dorsalmost portion of the gill opening in specimens of all ages.

Stage observed from 49 to 60 days after hatching. Sato Y, Godinho HP.


Cruciglanis pacifici has the highest proportion of body depth indicating its relatively deep body, and Microglanis parahybae and M.

Description of eggs and larvae of jack mackerel Trachurus symmetricus and distribution and abundance of larvae in and Arratia G, Schultze H-P. Individuals were reared from natural spawning of wild adults in flowing water.

The present observations also corroborate the Theory of Saltatory Ontogeny [ 25 ], since development alternated through periods of slow and small changes and fast and large changes. The greatest morphological changes in the development of L.

Head and body slightly pigmented with dendritic chromatophores containing dark pigment. IMCN1, Spurious ray [ 20 ] present at the end aledandri pectoral-fin spine since early in larval development 9 daysand persist in adults. Body and head distinctly depressed Fig 5a ; head approximates hexagonal shape in dorsal view Fig 5bwider than long; area of frontal bone depressed, concave in coronal section with conspicuous bony ridges.

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New interpretations on the phylogenetic characters related to these changes are provided in view of the two alternative hypotheses of the evolution of Pseudopimelodidae. Correlation analyses were carried out using Microsoft Excel, and box lophiiosilurus analysis using Past v. These serrations are absent in yolk sac and flexion stage larvae, and began to develop in larvae of postflexion stage.

The present study contributes with details on the early development of the external morphology in L. Initially the dorsalmost rays of the caudal-fin upper lobe are longest than the other lophjosilurus. USNMholotype, Early life history stages of fishes and their characters Ontogeny and Systematics of Fishes. The analysis presented herein shows that the study of the development of Lophiosilurus alexandri helps to determine the limits and polarity of the character states related to the evolution of the Pseudopimelodidae, especially for sister taxa relationships, such as those of Batrachoglanis and MicroglanisLophiosilurus and Cephalosilurusand Cruciglanis and Pseudopimelodusconditions observed in larval and juvenile stages of L.

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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 head and body.

Esqueleto caudal de peces Siluriformes y sus tendencias evolutivas. However, in Batrochoglanis and Microglanisthe axillary gland is absent in adults, a synapomorphy for a clade uniting those genera [ 911 ], most likely due to a paedomorphic event. Introduction The search for the morphological changes that gave rise to the present diversity of forms and taxa continues to be one of the main goals of Evolutionary Biology.

Actinopterygii, Lophiidae and Squatina spp.

The dorsalmost rays of the upper caudal-fin lobe are also longest in larvae of Batrochoglanis raninus [ 28 ], indicating that this condition may be also present in the remaining Pseudopimelodidae. The caudal skeleton of basal teleosts, its conventions, and some of its major evolutionary novelties in a temporal dimension In: Stage observed on day 3 of development; standard length 8. Exogenous feeding is possible after day 3 when the mouth opens.

Dorsal fin well developed with lophioeilurus, thick, strong anterior spine and six soft rays.

Lophiosilurus alexandri

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.

Box plot of standard length by age in days x-axis of Lophiosilurus alexandri. Accessed Dez