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.
|Published (Last):||10 December 2006|
|PDF File Size:||11.42 Mb|
|ePub File Size:||17.8 Mb|
|Price:||Free* [*Free Regsitration Required]|
Therefore, given its large size, unique shape, and controversial phylogenetic position, L. Abstract Pseudopimelodidae are Neotropical catfishes characterized by having slightly to strongly depressed body in fully developed specimens. Published online Apr Alecandri ray [ 20 ] present at the end of pectoral-fin spine since early in larval development 9 daysand persist in adults.
The most plesiomorphic condition is possibly present in the larvae of all species of Pseudopimelodidae, and in fully developed specimens of Cephalosilurus albomarginatus and Microglanis iheringi. Conversely, the maxillary barbel in Heptapteridae and Pimelodidae show positive allometric lophiosilhrus [ 14 ].
Primordial fin well developed in alexamdri stage of postflexion, surrounding the entire perimeter of trunk and tail; restricted to posterior regions of adipose and anal fins after day Generelle Morphologie der Organismen: A third state, mouth slightly superior, is present in adult Pseudopimelodus and some Microglanis. Twenty-three measurements were obtained on juveniles using a digital caliper accurate to 0.
Therefore, the relative depth of the body is a phylogenetic character with at least two states perhaps more, if a more accurate morphometric analysis is performeda relatively deep body being plesiomorphic and a relatively depressed body being apomorphic.
Head and body slightly pigmented with dendritic chromatophores containing dark pigment. Ortega-Lara A, Lehmann Alecandri.
At 42 days, hooks on anterior and posterior margins of pectoral-fin spine similar in size Fig lophiosilurys. The coloration of adult specimens of Lophiosilurus is greatly marked by the presence of widespread dark dendritic chromatophores, forming an overall dusky ground color.
Its head is extremely depressed, wider than long, the eyes are dorsal, and the mouth is wide and prognathous [ 7 ]. Anal fin well developed on day 8, but still associated with primordial fin; final development lophiosiulrus anal fin on day Adipose fin defined after 42 days. AMNH5, However, the condition in larvae and juveniles of Lophiosilurus is similar to the one present in the other species of pseudopimelodids.
The highly depressed body shape is also convergent in some well-known species of benthic fish marine such as Lophius spp. The Evolution of Ontogeny. Box plot of standard length by age in days x-axis of Lophiosilurus alexandri. Caudal, pectoral and alexandrii fins largely hyaline, with sparse dark chromatophores Fig 5a.
Species of most genera of Pseudopimelodidae also present a well-developed lateral line that extends on the body from head to caudal-fin base. Even though fully developed specimens of the latter have the coloration of Lophiosilurusjuveniles of C. Primordial anal fin broadly rounded, visible as thick membrane alexanndri within in ventral finfold. Pectoral fin, when adpressed, reaching vertical through base of fourth ray of dorsal fin, but not reaching pelvic fin.
Universidade Federal Rural de Pernambuco. Lophiosiurus caudal fin wing shaped, visible within confluent portions of dorsal and ventral finfolds; hypurals forming as cartilage. Buds of maxillary and mentonian barbels present only within the 1 st day of development. Lateral view of larvae of Lophiosilurus alexandri: Axillary gland visible above alexandti of pectoral fin.
Pectoral girdle well developed, particularly cleithral bulge and posterior cleithral process. The presence of an incomplete lateral line on the body is most likely due to a paedomorphic event, and is a putative synapomorphy for a clade composed of Batrochoglanis and Microglaniscorroborating previous hypotheses [ 911 ]. Reevaluation of the caudal skeleton lophisoilurus certain actinopterygian fishes: 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.
The extreme condition in L. Anal-fin base shorter than adipose-fin base. The lophiosiurus of the mouth has also undergone major changes during the development of Lophiosilurus. Early life histories of fishes: Dorsal region of skull with several ridges on day Material Examined Lophiosilurus alexandri: Pectoral fin, when adpressed, reaching vertical through end of dorsal-fin base and slightly alecandri origin of pelvic fin. Correlation analysis of body proportions related to body width and depth of larvae and juveniles of Lophiosilurus alexandri yielded a large dispersion, but with a tendency of increase the width over depth, as indicated by the regression line Fig 8.