English

Campos Lima Fabiano,Nunes Souto Cristiele,Luiz Quagliatto Santos Reacute,Borges Salgueiro De Simone Simone,Helena Santesso Teixeira Socirc Nia,De Arauacute Jo Martins Clarissa,Gonccedil Alves Vieira Luceacute Lia,Eduardo Coutinho Marcos

doi:10.5897/sre12.360

Abstract

Caiman yacare embryos were collected and subjected to the bone cleared and Alizarin staining to analyze the ontogenic patterns of the skeletal ossification of the pelvic girdle and members. Ossification of C. yacare pelvis begins at 36 days of incubation. The femur, tibia and fibula present simultaneous stain retention at 30 days. It has four tarsal bones, the calcaneus, the talus, distal III and distal IV. Their ossification starts with the calcaneus from the 40th day of incubation, followed by the talus. At 54 days, the distal tarsal IV is conspicuous, as is the outline of the distal III. Each foot has five metatarsi (MT) and 13 phalanges (phalangeal formula 2:3:4:4). Ossification of the metatarsi begins at 36 days and follows the sequence MTI=MTII=MTIII=MTIV>MTV. The first phalanges begin the ossification process on the 36th day and continue up to the last day of incubation. The sequence of ossification of the proximal phalanges is PPI=PPII=PPIII>PPIV, while that of the medial phalanges is MPII> MPpIII>MDpIII>MPpIV>MDpIV and that of the distal phalanges is DPI>DPII>DPIII>DPIV, and the ontogenic pattern of the bones of the pelvic girdle and members of C. yacare differs from that of other reptiles, albeit with a few similarities. Key words: Alizarin, morphology, ossification, pantanal caiman, reptiles.

Highlights

Vertebrates have a unique skeleton that is composed of a set of plastic structures that are able to grow, adapt and repair themselves due to the wide morphological and architectural diversity of the skeletal tissue (White et al, 2003; Hildebrand and Goslow, 2006)
Endochondral ossification is the main process governing the formation of leg bones, which derive from a cartilaginous base (Shubin and Alberch, 1986); the sequence of temporal, dynamic and specific events, in which it occurs are poorly defined (Burke and Alberch, 1985; White et al, 2003; Fabrezi et al, 2007)
Ossification of the pelvic girdle begins from Day 36 of incubation with the presence of stain retention in the ilium bone; ossification process continues to the pube and ischium at Day 39, which reaches a very advanced stage at 51 days

Summary

Introduction

Vertebrates have a unique skeleton that is composed of a set of plastic structures that are able to grow, adapt and repair themselves due to the wide morphological and architectural diversity of the skeletal tissue (White et al, 2003; Hildebrand and Goslow, 2006). Lima et al 2149 contributions of Rieppel (1993a, b, 1994a), Sheil (2003b) and Vieira and Santos (2007), in the study of the skeletal ossification of Alligator mississippiensis, Chamaeleo hoehnelii, Macrochelys teminckii and Podocnemis expansa, In these animals, endochondral ossification is the main process governing the formation of leg bones, which derive from a cartilaginous base (Shubin and Alberch, 1986); the sequence of temporal, dynamic and specific events, in which it occurs are poorly defined (Burke and Alberch, 1985; White et al, 2003; Fabrezi et al, 2007). Müller and Alberch (1990) suggested the existence of several hypotheses based on anatomical studies of the skeleton in crocodilians that have undergone diverse changes during the evolutionary process, especially with regard to the number of phalanges and carpal and tarsal bones, many of these changes due to the characteristics of organisms which are seen as mechanical devices to maintain their biomechanics and function, alter their shape (Pounds et al, 1983)

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