Effects of light-dark cycle on the spatial distribution and feeding activity of fish larvae of two co-occurring species (Pisces: Hypophthalmidae and Sciaenidae) in a Neotropical floodplain lake

Abstract

Most studies on mechanisms regulating fish larvae processes have focused on assessing the isolated effects of food distribution and feeding behavior. However, in natural ecosystems, fish larvae may strongly interact with zooplankton organisms in an array of complex, direct and indirect interdependencies. This study analyzed the spatial distribution, diet and feeding behavior of early stages of Hypophthalmus edentatus and Plagioscion squamosissimus, two fish species co-occurring in an isolated floodplain lake, during the light-dark cycle. Larvae fed more actively during dark periods (dusk and night) when they migrated toward the surface of the lake, and remained on the bottom and fed less during light periods (day and dawn). Cladocerans represented the most frequent prey in the diet of H. edentatus larvae. In turn, P. squamosissimus larvae initially preferred cladocerans and, as they developed, included calanoid copepods in the diet. Significant differences were detected in the frequencies of food items consumed during larval development, which could be related to a better ability of the most developed stages to explore the environment in search of other prey.Keywords: diet, predation, feeding preference, trophic strategy, zooplankton.Efeitos do ciclo claro-escuro na distribuição espacial e na atividade alimentar de larvas de peixes de duas espécies coexistentes (Pisces: Hypophthalmidae e Sciaenidae) em uma lagoa de planície de inundação Neotropical ResumoA maioria dos estudos de mecanismos que regulam os processos de larvas de peixes se concentra na avaliação dos efeitos isolados da distribuição do alimento e do comportamento alimentar. No entanto, em ecossistemas naturais, as larvas de peixes podem interagir fortemente com os organismos do zooplâncton em uma série de interdependências complexas, diretas e indiretas. Este estudo analisou a distribuição espacial, dieta e comportamento alimentar dos estágios iniciais de vida de Hypophthalmus edentatus e Plagioscion squamosissimus, duas espécies de peixes coexistentes em uma lagoa isolada de planície de inundação, durante o ciclo claro-escuro. As larvas se alimentaram mais ativamente durante os períodos escuros (crepúsculo e noite) quando ascenderam em direção à superfície da lagoa, enquanto durante os períodos luminosos (dia e amanhecer) permaneceram no fundo e pouco se alimentaram. Os cladóceros foram as presas mais frequentes na dieta de larvas de H. edentatus. Por sua vez, larvas de P. squamosissimus inicialmente preferiram cladóceros, e a medida que se desenvolveram incluíram copépodes calanóides na dieta. Diferenças significativas foram detectadas nas frequências dos itens alimentares consumidos durante o desenvolvimento larval, o que poderia estar relacionado a uma melhor capacidade dos estágios mais desenvolvidos em explorar o ambiente na busca por outras presas.Palavras-chave: dieta, predação, preferência alimentar, estratégia trófica, zooplâncton.

Seasonal distribution of fish larvae in mangrove-seagrass seascapes of Zanzibar (Tanzania)

“…The overall high proportion of postflexion individuals observed in this study might partly be a result of the methodology used, i.e. the daytime horizontal surface hauling using plankton net in very shallow, tidally influenced nearshore areas, as smaller flexion and preflexion larvae may be found in deeper waters during daytime 75 . The mixture of individuals from all growth stages (including also 2% juveniles and adults sampled occasionally in the plankton net), however, indicates that the majority of fish larvae recorded in this study completed their pelagic phase in the same habitats, as shown by Pattrick & Strydom 63 .…”

Ontogenetic structure and distribution patterns of ichthyoplankton in the confluence zone of two river systems in the Eastern Amazon

“…The predominance of Clupeiformes (Engraulidae) and Perciformes ( P. squamosissimus ) larvae in more advanced stages of development at the mouth of the Tapajós river may be related to the favorable conditions of this environment, such as high water transparency, primary and secondary productivity (Oliveira & Ferreira, 2008; Silva & Bialetzki, 2019). This ensures greater availability and obtaining of food for these taxonomic groups, such as algae and zooplankton (Makrakis et al., 2005; Neves et al., 2015), in addition to reducing interspecific competition (Picapedra et al., 2018), reinforcing the importance of tributaries as breeding sites for small and medium‐sized species, which have a sedentary behavior or short reproductive migration.…”

Vision‐mediated feeding behaviour of early juvenile Sultan fish,Leptobarbus hoevenii

“…In striped bass Morone saxatilis , ablation of free neuromasts had a negative effect on feeding (Sampson et al., 2013), and free neuromasts are involved in prey detection and feeding of the willow shiner Gnathopogon elongatus caerulescens (Mukai, 2006; Mukai et al., 1994). The senses used for prey detection and feeding of freshwater fish are species‐specific (Picapedra et al., 2018) and the information about sensory modality of feeding in the early life‐history stages of freshwater fish is limited.…”

“…However, the ingestion of Moina facilitated exclusively by the mechano‐ or chemoreception was far much lesser than that by the vision. Non‐visual feeding is common in early life‐history stages of freshwater fish (Mookerji & Rao, 1993; Mukai & Lim, 2011; Mukai et al., 2010; Picapedra et al., 2018). Unexpectedly, this study clearly demonstrated that the L. hoevenii juveniles used mainly vision for prey detection and capture.…”