Yolk Absorption Rate and Mouth Development in Larvae of Dormitator latifrons (Perciformes: Eleotridae)

Abstract

Fish larvae suffer high starvation mortality during the transition from yolk absorption to exogenous feeding, and the size of the developing buccal structures limits the food they can consume. Determining the suitable timing and size of live or inert foods could decrease this mortality. We described mouth development and determined the yolk absorption rate and point-of-no-return (PNR) of Dormitator latifrons larvae. One male and one female specimen were induced to spawn using salmon GnRHa implants, and 45 of their larvae were sedated and observed under a microscope every 24 h to measure total length, standard length, yolk sac length, yolk sac width, oil globule length, oil globule width, width of the oesophagus, and length of the upper and lower jaw longitudinal. The growth model, maximum mouth opening, daily survival, and starvation period were determined. The larval growth was fastest during the first 24 h post−hatching (HPH) at 28 ± 1 °C with an average increase of 625.42 µm in total length and 573.51 µm in standard length. The highest percentage of yolk absorption (52%) occurred within 24 HPH and at 96 HPH the yolk sac was completely reabsorbed. The PNR was reached at 156.41 HPH (p < 0.05). At 96 HPH, the upper and lower jaw were distinguishable by mouth movements. Our results suggest that the larvae of D. latifrons should be fed at 96 HPH with prey measuring 50–65 µm.

Adaptation and domestication of endangered wild betta fish (Betta channoides) originating from East Kalimantan, Indonesia

“…The signi cance of monitoring yolk absorption in early larval development is underscored by a positive linear equation for the YAR (y = 14.24x -7.1886) and a negative linear equation for the decrease in Vy (y = 0.2221x + 1.6721). Various factors in uence the absorption rate of sh egg yolk, including egg and larval size, Vy, incubation temperature, oxygen concentration, and metabolic activity of the absorptive layer (Pepin et al 1997;Jardine and Litvak 2003;Reyes-Mero et al 2022;Syafariyah et al 2023). Yolk absorption follows a sequential pattern, with yolk platelets mobilizing faster than the oil globules after hatching (Kamler 2008).…”

Captive breeding of endangered betta fish, Betta rubra, under laboratory conditions

“…Fisheries and Aquatic Sciences and larvae, the volume of the yolk, the incubation temperature, oxygen concentration, and metabolic activity of the absorptive layer (Jardine & Litvak, 2003;Mero et al, 2022;Pepin et al, 1997;Reyes-Syafariyah et al, 2023). Yolk absorption occurs in a sequence, with yolk platelets being mobilized more rapidly than the oil globule after hatching (Kamler, 2008).…”

Efecto de la ración alimentaria en la acumulación amonio y supervivencia de Dormitator latifrons

“…El chame (D. latifrons) es un pez dulce acuícola de la familia Eleotridae, con potencial para la acuicultura debido a su elevada tolerancia fisiológica ante la variabilidad ambiental, rápido crecimiento y bajos requerimientos nutricionales (14). Tan solo en Ecuador se realizan cultivos comerciales basados en sistemas extensivos y captura de semilla del medio natural, logrando exportar entre 800 y 1000 t de chame al año (15); pero tanto Ecuador como otros países de la región donde se distribuye D. latifrons, han incrementado su interés por el desarrollo de tecnología acuícola para esta especie (16,17), lo que ha forzado el desarrollo de investigaciones sobre temáticas nutricionales, de condiciones de cultivo y de enfermedades. Esto ha motivado que actualmente en Ecuador algunos productores hayan intensificado sus cultivos con densidades de siembra entre 25 a 35 organismos por m 2 y suministro continuo de alimento balanceado para camarón durante todo el período de engorde Muñoz-Chumo et al -Ración de alimento y amonio en Dormitator latifrons (18), aunque densidades de siembra de 60 peces por m 2 y 80 peces por m 3 también han sido utilizadas en condiciones experimentales (19,20).…”