Desenvolvimento embrionário, larval e juvenil de Hemisorubim platyrhynchos (Siluriformes, Pimelodidae) da bacia do rio Paraná

Abstract

ABSTRACT. Embrionic, larval and juvenile development of Hemisorubim platyrhynchos (Siluriformes, Pimelodidae) from the Paraná River basin. 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 in juveniles (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. KEYWORDS.Early development, morphometry, allometric growth, fish larvae. RESUMO.O objetivo deste estudo foi descrever o desenvolvimento embrionário, larval e juvenil da jurupoca, Hemisorubim platyrhynchos (Valenciennes, 1840), bem como as mudanças nos padrões de crescimento alométrico durante a ontogenia inicial da espécie. Um total de 90 ovos, 210 larvas e 24 juvenis provenientes de reprodução induzida foram analisados quanto a variáveis morfométricas e merísticas, além do coeficiente de crescimento alométrico em relação à cabeça, tronco e cauda durante o período larval e juvenil inicial. Os ovos apresentaram diâmetro médio de 1,74 mm, espaço perivitelino amplo (21,29%), com média de 0,37 mm, e diâmetro médio do vitelo de 1,08 mm. O comprimento padrão (CP) das larvas variou de 3,47 a 11,85 mm, com a maioria das medidas apresentando aumento proporcional ao longo do desenvolvimento. O número total de miômeros variou de 40 a 46 (pré-anal=15-17 e pós-anal=24-30). As larvas iniciais de H. platyrhynchos apresentam pigmentação na cabeça e na região ântero-ventral do corpo (anterior e posterior do saco vitelino). No estágio de pós-flexão, a pigmentação se intensifica, distribuindo-se na região dorsal da cabeça, formando uma faixa longitudinal que se estende do focinho ao opérculo, assim como uma faixa transversal, d...

Characterization of the early development of Pseudoplatystoma reticulatum Eigenmann & Eigenmann, 1889 (Siluriformes: Pimelodidae) from the Paraguay River Basin

“…This may be an adaptation to improve embryo survival by protecting it against damage (Andrade-Talmelli et al, 2001;Sanches et al, 2001). This characteristic is common among migratory species that spawn in lotic environments, such as Salminus brasiliensis (Cuvier, 1816) , Brycon orbignyanus (Valenciennes, 1850) (ReynalteTataje et al, 2004), Pseudoplatystoma corruscans (Spix & Agassiz, 1829) , and Hemisorubim platyrhynchos (Valenciennes, 1840) (Andrade et al, 2014). Pérez et al (2001) reported for Pseudoplatystoma fasciatum (Linnaeus 1766), at an average temperature of 25.5 ºC, the morula stage with 2h 15min, the gastrula stage at the fourth hour of incubation, and embryo differentiation starting at the seventh hour of incubation.…”

Larval development of mandi‐pintado Pimelodus britskii (Siluriformes: Pimelodidae)

“…, Hemisorubim platyrhynchos (Valenciennes 1840), Pimelodus maculatus Lacépède, 1803, Pseudoplatystoma corruscans (Spix 1829) and Sorubim cf. lima (Bloch & Schneider 1801)) and it is difficult to differentiate these species, especially when they occur in the same river basin (Andrade et al ., ). In this study, we observed overlapping numbers of myomeres in the pre‐flexion stages of P. britskii , P. ortmanni and P. maculatus.…”

“…The expansion of melanophores in later stages may provide camouflage as the larvae begin to occupy structured areas, usually at river margins or in sheltered habitats (Nakatani et al, 2001). The pigmentation pattern of P. britskii is similar to that of several Pimelodidae species (e.g., Hemisorubim platyr- 1801)) and it is difficult to differentiate these species, especially when they occur in the same river basin (Andrade et al, 2014).…”

Characterization of the initial ontogeny ofLeiarius marmoratus(GILL, 1870): larvae to juvenile

“…The total number of myomers varied from 49 to 56, presenting a slight overlap with P. corruscans with 45 to 50 myomers (Nakatani et al, ), Sorubim cf . lima with 48 to 52 (Nakatani et al, ), Hemisorubim platyrhynchos with 40 to 46 (Andrade et al, ) and P. reticulatum with 45 to 50 (Andrade et al, ).…”

“…Despite the large number of freshwater teleost species currently known, few studies address ontogenetic aspects. Being the surveys more focused on evolutionary, ecological or descriptive aspects for several fish species from different watersheds (Andrade et al, ; Arashiro et al, ; Assega, Birindelli, Bialetzki, & Shibatta, ; Bialetzki et al, ; Costa & Neto, ; Faustino, Makino, Neumann, & Nakaghi, ; Gavaia, Dinis, & Cancela, ; Honji, Tolussi, Mello, Caneppele, & Moreira, ; Maciel, Júnior, Donzele, Lanna, & Menin, ; Miquelarena, Ortubay, & Cussac, ; Suzuki & Pompeu, ; Vrtílekv & Reichard, ; Zacardi, Silva, Bittencourt, Costa, & Nakayama, ). Thus, there is a gap regarding the ontogenetic aspects of these species, which is a fundamental knowledge as a support for taxonomic and fisheries biology studies.…”