ABSTRACT This study aimed to assess the growth performance of bullfrog (Aquarana catesbeiana) tadpoles subjected to different management practices and diets. Two distinct feeding management strategies were evaluated: broadcast feeding and the use of a trough. Regarding the diet, two formulations were tested: the first involved feed with 28% crude protein (CP) for the initial 30 days, followed by feed with 36% CP for the subsequent 30 days; the second treatment consisted of a commercial feed designed for tropical carnivorous fish, containing 40% CP, administered throughout the experimental period (60 days). The experiment was conducted in sixteen 30-L containers, each undergoing a daily water renewal of 200% of its volume, and tadpoles were stocked at a density of one tadpole/L (0.081±0.075 g initial weight). Growth performance was evaluated. The experimental design was factorial (2 × 2) with four replicates. Data were analyzed using analysis of variance and Tukey’s test (α = 0.05). Tadpoles fed the commercial feed outperformed (final weight of 3.329 g (FW), feed conversion (FC) of 1.423 g/g, and protein efficiency rate (PER) of 1.578 g/g) those fed the experimental diets in all growth performance parameters except for PER, whose best results were achieved with the experimental diets (FW of 2.708 g; FC of 1.579 g/g, and PER of 1.880 g/g). Regarding management practices, the use of a trough yielded (FC of 1.409 g/g) superior outcomes compared with the traditional method (FC of 1.579 g/g); therefore, the combination of a trough and the commercial feed regimen demonstrated the best results. Aquarana catesbeiana evaluated diet tested 28 (CP 3 days 36 fish 40 60 (6 days. . days) 30L L containers 200 volume tadpoleL tadpole 0.081±0.075 00810075 0 081 075 (0.081±0.07 weight. weight) 2 ( replicates Tukeys Tukey s α 0.05. 005 0.05 05 0.05) final 3329 329 3.32 FW, FW , (FW) 1423 1 423 1.42 gg g/g (PER 1578 578 1.57 2708 708 2.70 1579 579 1880 880 1.88 g/g. 1409 409 1.40 therefore 4 6 20 0.081±0.07 0081007 08 07 (0.081±0.0 00 0.0 332 32 3.3 142 42 1.4 157 57 1.5 270 70 2.7 188 88 1.8 140 0.081±0.0 008100 (0.081±0. 0. 33 3. 14 1. 15 5 27 7 2. 18 8 0.081±0. 00810 (0.081±0 0.081±0 0081 (0.081± 0.081± 008 (0.081 0.081 (0.08 0.08 (0.0 (0. (0

Os objetivos do presente trabalho foram estudar a anatomia funcional e a morfometria comparativas nos intestinos médio e no reto, do peixe Teleostei, surubim, Pseudoplatystoma coruscans (Agassiz, 1829) (Siluriformes, Siluroidei, Pimelodidae), de hábito alimentar carnívoro, em duas classes de tamanho, visando fornecer referência à nutrição para o ajuste de diferentes sistemas de alimentação artificial para essa espécie nativa. Por meio destes estudos concluiu-se que o intestino do surubim, sob o ponto de vista morfológico, deve ser denominado, de intestino médio e reto, devido a presença da valva ileorretal e da invaginação valvar intestinal entre esses segmentos. Em relação ao padrão de enrolamento do intestino, apesar do plano geral do intestino médio e do reto ter sido mantido, as alças do intestino médio apresentaram arranjo indefinido, não tendo sido determinado um arranjo-padrão para a espécie. O arranjo intestinal é compatível ao da maioria de peixes carnívoros, ou predominantemente carnívoro, uma vez que seu intestino é quase retilíneo; contudo, as circunvoluções das alças finais do intestino médio talvez possam ser vistas como adaptações a um possível regime onívoro, preferencialmente carnívoro. As pregas intestinais encontram-se mais complexas e desenvolvidas no intestino dos exemplares da segunda classe de tamanho. Procurando estabelecer relações entre o arranjo das pregas das mucosas e a velocidade de transporte do alimento no intestino médio da espécie estudada, sugere-se que o padrão longitudinal, com numerosas anastomoses retardam o avanço do alimento em sentido aboral, o que possibilita maior período digestivo e, conseqüentemente, maior aproveitamento dos nutrientes, pela exposição do material alimentar à mucosa intestinal por período maior, além de contribuir para a preparação do bolo fecal. As pregas da mucosa próxima ao ânus têm direção longitudinal, sugerindo auxílio na expulsão dos bolos fecais, direcionando-os para o meio exterior.

The objectives of this work were to study the functional anatomy and the comparative morphometry in the medium intestine and in the rectum of Teleostei, surubim, Pseudoplatystoma coruscans (Agassiz, 1829) (Siluriformes, Siluroidei, Pimelodidae), with carnivorous feeding habits, in two size classes, aiming to provide nutritional data for the adjustment of different artificial feeding system. It was concluded that the surubim intestine, under a morphological view, must be called of medium intestine and rectum, due to the presence of ileo-rectal valve and of intestinal valve invagination among these segments. In relation to the intestinal widding pattern, although the overall arrangement of the medium intestine and rectum was maintained, the medium intestine rings showed undefined arrangement, and an standard arrangement could not be determined for the specie. The intestinal arrangement was compatible to the most carnivorous fishes, or predominantly carnivore, once the intestine is almost ret; however, the circunvolutions of intestine final rings of medium intestine can be considered adaptations of a possible omnivorous feeding, preferentially carnivorous. The intestinal fold were more complex and developed in the intestine of the second size class species. In order to establish the relations among the mucous fold arrangement and the o food transportation speed in the medium intestine of the studied specie, it is suggested that the longitudinal pattern, with several anastomoses delay the feed progress in the aboral direction, allowing a larger digestive period and, consequently, better feed nutrients profit, by the feed material exposition to the intestinal mucous for larger period, besides contributing for the fecal mass preparation. The mucous fold next to the anus have longitudinal direction, contributing for the fecal bolos expulsion, directing them to the exterior environment.

O objetivo do presente trabalho foi o de verificar a presença de células endócrinas nos intestinos médio e posterior, ou reto, e nos cecos pilóricos de três espécies tropicais de peixes Teleostei de água doce com hábitos alimentares diferentes: piracanjuba, (Brycon orbignyanus) e piau (Leporinus friderici), onívoro; e surubim (Pseudoplatystoma coruscans), carnívoro. Para tanto, foram utilizados sete exemplares da piracanjuba, com médias de peso e comprimento-padrão de 410,16 ± 66,33 g e 27,42 ± 1,17 cm, respectivamente, 13 exemplares de piau com médias de 77,71 ± 24,31 g e 14,84 ± 1,56 cm de peso e comprimento-padrão, respectivamente; e cinco exemplares do surubim com médias de peso e comprimento-padrão de 309,91 ± 94,23 g e 32,70 ± 1,79 cm, respectivamente. Pode-se constatar a presença de células endócrinas do "tipo aberto" nos segmentos referentes aos intestinos médio e posterior das espécies onívoras e do "tipo fechado" no intestino médio e no reto da espécie carnívora. As células argirófilas foram observadas entre as células absortivas do epitélio intestinal. Os resultados permitem concluir que a presença de células endócrinas nas espécies estudadas pode indicar que estas atuam no mecanismo de controle da absorção dos nutrientes do alimento.

The objective of this work was to verify the presence of endocrine cellules in the medium and posterior intestines, or rectum, and in the piloric cecum in three tropical freshwater Teleostei species with different feeding habits: piracanjuba, (Brycon orbignyanus) and piau (Leporinus friderici) omnivorous; and surubim (Pseudoplatystoma coruscans), carnivore. Seven exemplars of piracanjuba, with average weight and standard length of 410.16 ± 66.33 g and 27.42 ± 1.17 cm, respectively, 13 exemplars of piau with average weight and standard length of 77.71 ± 24.31 g and 14.84 ± 1.56 cm, respectively; and five exemplars of surubim with average weight and standard length of 309.91 ± 94.23 g and 32.70 ± 1.79 cm, respectively, were used. The presence of endocrine cellules like "open" was verified on the segments related to the medium and posterior intestines omnivores species and like "closed" in the medium intestine and in the rectum of the carnivore specie. The argirofiles cellules were observed among the as absortive cellules of intestinal epithelium. The results showed that the presence of endocrine cellules can indicate that the studied species act in the absorption control mechanism of food nutrients. However, due to the obtained amounts, more studies are necessary to elucidate this control.