Embrionic, larval and juvenile development of Hemisorubim platyrhyncos (Siluriformes, Pimelodidae) from the Parana River basin

• Published in: Iheringia. Série zoologia 2014-03, Vol.104 (1), p.70-80
• Main Authors: Andrade, Fernanda F, Makrakis, Maristela C, de Lima, Ariane F, de Assumpcao, Lucileine, Makrakis, Sergio, Pini, Suelen F R
• Format: Article
• Language: Portuguese
• Subjects: Brackish; Pimelodidae; Siluriformes
• ISSN: 0073-4721; 1678-4766

This study aimed to describe the initial stages of development of the Pothole Shovelnose Catfish, Hemisorubim platyrhynchos (Valenciennes, 1840), as well as changes in the allometric growth pattern during early ontogeny. A total of 90 eggs 210 larvae, and 24 juveniles from hatching were analyzed for morphometric and meristic variables, and for besides the allometric growth coefficient in relation to head, trunk, and tail during larval and initial juvenile period. The eggs presented 1.74 mm of mean diameter; ample vitelline space (21.29%) with mean of 0.37 mm; and the average diameter of the yolk was 1.08 mm. The standard length (SL) of the larvae ranged from 3.47 to 11.85 mm, with most measurements a presenting proportional increase throughout development. The total number of myomeres ranged from 40 to 46 (pre-anal=15-17 and post-anal=24-30). The early larvae of H. platyrhynchos present pigmentation in the head and in the anteroventral region of the body (anterior and posterior regions of the yolk sac). The pigmentation intensifies in the post-flexion stage along the dorsal region of the head, forming a longitudinal strip extending from the snout to the operculum, as a transversal strip that goes from one side to the other, passing through the anterior region of the dorsal fin, with maculae distributed throughout the body injuveniles (SL=19.5-49.09 mm). In the early stages of larval development, the head and tail grow much faster than the trunk, indicating priorities related to food and swimming, which tend to isometry, with fast growth of the trunk in early juveniles.Original Abstract: O objetivo deste estudo foi descrever o desenvolvimento embrionario, larval e juvenil da jurupoca, Hemisorubim platyrhynchos (Valenciennes, 1840), bem como as mudangas nos padroes de crescimento alometrico durante a ontogenia inicial da especie. Um total de 90 ovos, 210 larvas e 24 juvenis provenientes de reproducao induzida foram analisados quanto a variaveis morfometricas e meristicas, alem do coeficiente de crescimento alometrico em relagao a cabeca, tronco e cauda durante o periodo larval e juvenil inicial. Os ovos apresentaram diametro medio de 1,74 mm, espaco perivitelino amplo (21,29%), com media de 0,37 mm, e diametro medio do vitelo de 1,08 mm. O comprimento padrao (CP) das larvas variou de 3,47 a 11,85 mm, com a maioria das medidas apresentando aumento proportional ao longo do desenvolvimento. O numero total de miomeros variou de 40 a 46 (pre-anal=15-17 e pos-anal