Early ontogenesis of the angelfish, Pterophyllum scalare Schultze, 1823 (Cichlidae)

Abstract

This study describes the egg membrane structures of angelfish (Pterophyllum scalare), morpho-physiological changes during angelfish embryogenesis from activation to hatching under optimal conditions (28°C; pH 6.8), the developing larvae and fry, the effect of alkaline pH on the early developmental stages of the species, the relationship between food item size and fry survival. Egg membranes (thin, transparent, 1.67-2.18 µm thick) are covered by a sticky substance. The amber-coloured angelfish eggs were oval in shape, with average diameters of 1.436 and 1.171 mm, i.e., a mean volume of 1.033 ± 0.095 mm 3 . The survival rate of embryos and larvae kept in water with an elevated, slightly alkaline pH was very low: as few as 2% of the embryos survived, while in the batch kept in optimal water conditions very few eggs died. The first larvae hatched after 1288 h of embryonic development. The newly hatched larvae measured on average 2.60 ± 0.093 mm and had large (0.64 ± 0.077 mm³) yolk sacs. They attached themselves to the substrate with a secretion of thin, viscous threads, which was released from glands situated on the top of the head. The glands vanished on day 5. The 1-day-old larvae showed the first pigment cells on the body and the eyes of the 2-dayolds were already fully pigmented. Between day 4 and 5 of larval life, the larvae began feeding on live food. The 23-day-old fry looked like a miniature versions of the adults. Mortality of the angelfish larvae during their first days after hatching was higher in those fed brine shrimp (Artemia salina) nauplii than those fed protozoans and rotifers.En este trabajo se ha descrito la estructura de las túnicas ovulares del escalar o pez ángel (Pterophyllum scalare), las modificaciones morfo-fisiológicas que transcurren durante la embriogénesis del escalar desde el momento de activización para el desove en condiciones ambientales óptimas (28ºC y pH 6,8) y, se han caracterizado las larvas y los alevines desarrollándose. Adicionalmente, se ha estudiado el efecto del pH básico del agua sobre los primeros estadios de desarrollo y la dependencia entre la cantidad de alimento y la supervivencia de los alevines. Las túnicas ovulares del escalar son finas (1,67-2,18 mm), transparentes, cubiertas de una sustancia viscosa. Los huevos de color ámbar tienen forma ovalada de diámetros medios 1,436 y 1,171 mm y de un volumen medio de 1,033 ± 0,095 mm 3 . El porcentaje de supervivencia de embriones y de larvas en agua con pH aumentado, ligeramente básico, fue muy bajo, ya que sólo el 2% de los embriones sobrevivió, mientras que en agua de parámetros óptimos sólo algunos huevos palidecieron. Las larvas recién salidas del huevo medían 2,60 ± 0,093 mm por término medio y poseían grandes (0,64 ± 0,077 mm³) sacos vitelinos. Se han adherido al substrato mediante una secreción en forma de filamentos finos y viscosos. Esta secreción se ha desprendido de las glándulas ubicadas en la cumbre de la cabeza. Las glándulas desaparecieron al 5º día de vida de las larvas. Las larvas de un día poseían ya l...

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“…In a similar study, morpho-physiological changes was reported the early developmental stages of freshwater angelfish under different conditions (28°C; pH 6.8) (Korzelecka-Orkisz, 2012). Korzelecka-Orkisz et al, (2012) described the egg membrane structures of angelfish (Pterophyllum scalare), morpho-physiological changes and the developing larvae and fry, but they didn't report histolological changes of angelfish larvae on the early developmental stages.…”

“…Korzelecka-Orkisz et al, (2012) described the egg membrane structures of angelfish (Pterophyllum scalare), morpho-physiological changes and the developing larvae and fry, but they didn't report histolological changes of angelfish larvae on the early developmental stages. The main differences between these previous studies and our study is that reported not only morphological findings but also histological findings and allometric growth data.…”

“…Angelfish are quite popular around the world among aquarium hobbyist (Luna-Figueroa, 2003;Kasiri et al, 2011). Angelfish grow to 15 cm total length and 25 cm total height at the depth of 1-2 m under natural conditions (Mills, 1993;Korzelecka-Orkisz et al, 2012). They were characterized by specific reproductive behavior.…”

“…Larval stage, which is a critical stage in the lives of fish, is of great importance because this period involves functionaland morphological changes in internal organs, tissue systems and particularly in digestive systems (Govoni et al, 1986;Bisbal and Bengston, 1995;Meijide and Guerrero 2000;Elbal et al, 2004;Santamaría Marín de Mateo et al, 2004;Çelik, 2010;Çelik et al, 2011;Korzelecka-Orkisz et al, 2012). This study aims to understand morphologic and histologic changes observed in freshwater angelfish (Pterophyllum scalare) during ontogenic stage which lasts for 30 days from hatching and to obtain better rearing data.…”

Ontogenetic development of Heterocharax macrolepisEigenmann (Ostariophysi: Characiformes: Characidae) with comments on the form of the yolk sac in the Heterocharacinae

“…The remaining information on freshwater Neotropical larval fishes are scattered in separate papers often dealing with a single or a few species. These include studies on clupeiforms (e.g., Severi & Verani, 2006;Silva et al, 2010), siluriforms (e.g., Chacon, 1975;Godinho et al, 1978;Oldani, 1983a;Kossowski & Madrid, 1991;Cardoso et al, 1995;Sanches et al, 1999;Luz et al, 2001;Godinho et al, 2003;Lundberg et al, 2004;Feiden et al, 2005;Marques et al, 2008;Oliveira et al, 2008;Amorim et al, 2009;Faustino et al, 2010;Perini et al, 2010;Rodrigues-Galdino et al, 2010;Buzollo et al, 2011;Fuller, 2012;Honji et al, 2012;Nogueira et al, 2012;Weber et al, 2012), gymnotiforms (e.g., Kirschbaum & Schugardt, 2002) and perciforms (e.g., Prokes et al, 1987;Pena et al, 1988;Nakatani et al, 1997;Korzelecka-Orkisz et al, 2012), besides the Characiformes. More specifically within the latter order, most studies have focused on representatives of the Anostomidae (Godinho et al, 2003), Curimatidae (Araújo Lima, 1991;Perini et al, 2013), Cynodontidae (Sousa & Severi, 2002), Erythrinidae (Matkovic & Pisanó, 1989;Gomes et al, 2007;Bialetzki et al, 2008;Maciel et al, 2009;…”