Distinct skin morphological and transcriptomic profiles between wild and albino Oscar Astronotus ocellatus

SUMMARYWe characterized prey-capture strategies in seven species of cichlid fishes representing diverse trophic habits and anticipated feeding abilities. The species examined were Petenia splendida, Cichla ocellaris, Cichlasoma minckleyi, Astronotus ocellatus, Crenicichla geayi, Heros severus (formerly Cichlasoma severum) and Cyprichromis leptosoma. Three individuals per species were filmed with video at 500Hz as they captured live adult Artemia sp. and Poecilia reticulata. For each feeding sequence, we measured the contribution of predator movement towards the prey (i.e. ram) and the movement of prey towards the predator due to suction. The use of ram differed significantly among prey types and predator species, varying as much as sixfold across predator species. High values of ram resulted in high attack velocities. Jaw protrusion contributed as much as 50% to overall ram values in some species, verifying its role in enhancing attack velocity. Suction distance did not vary significantly among species. Diversity in prey-capture behavior was therefore found to reflect differences among species in the strategy used to approach prey. Limited variation in the distance from which prey were sucked into the mouth is interpreted as the result of an expected exponential decline in water velocity with distance from the mouth of the suction-feeding predator. We propose that this relationship represents a major constraint on the distance over which suction feeding is effective for all aquatic-feeding predators.

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Resistência ao estresse e crescimento de larvas de peixes neotropicais alimentadas com diferentes dietas

Pesquisa Agropecuária Brasileira ◽

10.1590/s0100-204x2007000100009 ◽

2007 ◽

Vol 42 (1) ◽

pp. 65-72 ◽

Cited By ~ 4

Author(s):

Ronald Kennedy Luz

Keyword(s):

Colossoma Macropomum ◽

Piaractus Mesopotamicus ◽

Astronotus Ocellatus

O objetivo deste trabalho foi avaliar o efeito da alimentação na resistência ao estresse e no crescimento de larvas das espécies de peixes neotropicais: Astronotus ocellatus (Oscar), Piaractus mesopotamicus (pacu) e Pseudoplatystoma coruscans (pintado). As larvas receberam diferentes tipos de alimentos (Artemia sp., larvas de Colossoma macropomum e dieta artificial Fry Feed Kyowa). Foram realizados testes de exposição ao ar e a taxa de sobrevivência, determinada 24 horas depois. A fim de avaliar o crescimento, medidas de peso foram realizadas em larvas dos diferentes tratamentos. Larvas de A. ocellatus alimentadas com náuplios de Artemia sp. apresentaram tendência de maior peso e resistência ao estresse, quando comparadas com o uso de dieta artificial. Larvas de P. mesopotamicus apresentaram melhores valores de peso e taxas de resistência ao estresse, quando alimentadas com Artemia sp. ou alimentação mista (Artemia sp. + dieta artificial). Em P. coruscans, o uso de larvas forrageiras resultou em indivíduos mais resistentes aos testes de exposição ao ar do que os que receberam apenas Artemia sp. Valores de peso, nos dois manejos alimentares, foram semelhantes entre si. O alimento vivo desempenha importante atuação no crescimento em peso e na melhora da resistência ao estresse das espécies estudadas.

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The Naturally Occurring Accommodative Response of the Oscar, Astronotus ocellatus, to Visual Stimuli

Vision Research ◽

10.1016/0042-6989(96)00048-x ◽

1996 ◽

Vol 36 (19) ◽

pp. 3021-3027 ◽

Cited By ~ 12

Author(s):

MARGOT E ANDISON ◽

JACOB G SIVAK

Keyword(s):

Visual Stimuli ◽

Accommodative Response ◽

Naturally Occurring ◽

Astronotus Ocellatus

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Small size today, aquarium dumping tomorrow: sales of juvenile non-native large fish as an important threat in Brazil

Neotropical Ichthyology ◽

10.1590/1982-0224-20170033 ◽

2017 ◽

Vol 15 (4) ◽

Cited By ~ 5

Author(s):

André L. B. Magalhães ◽

Mário Luis Orsi ◽

Fernando M. Pelicice ◽

Valter M. Azevedo-Santos ◽

Jean R. S. Vitule ◽

...

Keyword(s):

Management Strategies ◽

Biological Traits ◽

Large Fish ◽

Native Range ◽

Invasion Risk ◽

Pangasianodon Hypophthalmus ◽

Arapaima Gigas ◽

Geographical Regions ◽

Astronotus Ocellatus ◽

Amphilophus Citrinellus

ABSTRACT Informal sales of large-bodied non-native aquarium fishes (known as “tankbusters”) is increasing among Brazilian hobbyists. In this study, we surveyed this non-regulated trade on Facebook® from May 2012 to September 2016, systematically collecting information about the fishes available for trading: species, family, common/scientific names, native range, juvenile length, behavior, number of specimens available in five geographical regions from Brazil. We also assessed the invasion risk of the most frequently sold species using the Fish Invasiveness Screening Test (FIST). We found 93 taxa belonging to 35 families. Cichlidae was the dominant family, and most species were native to South America. All species are sold at very small sizes (< 10.0 cm), and most display aggressive behavior. The hybrid Amphilophus trimaculatus × Amphilophus citrinellus, Astronotus ocellatus, Uaru amphiacanthoides, Osteoglossum bicirrhosum, Cichla piquiti, Pangasianodon hypophthalmus, Datnioides microlepis and Cichla kelberi were the main species available. The southeast region showed the greatest trading activity. Based on biological traits, the FIST indicated that Arapaima gigas, C. kelberi and C. temensis are high-risk species in terms of biological invasions via aquarium dumping. We suggest management strategies such as trade regulations, monitoring, euthanasia and educational programs to prevent further introductions via aquarium dumping.

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Acoustic and visual adaptations to predation risk: A predator affects communication in vocal female fish

Current Zoology ◽

10.1093/cz/zoab049 ◽

2021 ◽

Author(s):

Isabelle Pia Maiditsch ◽

Friedrich Ladich

Keyword(s):

Sound Pressure ◽

Dominant Frequency ◽

Pressure Level ◽

Female Fish ◽

Predation Threat ◽

Calling Behaviour ◽

Sound Levels ◽

Astronotus Ocellatus ◽

Visual Signalling ◽

Ecological Constraint

Abstract Predation is an important ecological constraint that influences communication in animals. Fish respond to predators by adjusting their visual signalling behaviour, but the responses in calling behaviour in the presence of a visually detected predator are largely unknown. We hypothesize that fish will reduce visual and acoustic signalling including sound levels and avoid escalating fights in the presence of a predator. To test this we investigated dyadic contests in female croaking gouramis (Trichopsis vittata, Osphronemidae) in the presence and absence of a predator (Astronotus ocellatus, Cichlidae) in an adjoining tank. Agonistic behaviour in T. vittata consists of lateral (visual) displays, antiparallel circling and production of croaking sounds and may escalate to frontal displays. We analysed the number and duration of lateral display bouts, the number, duration, sound pressure level and dominant frequency of croaking sounds as well as contest outcomes. The number and duration of lateral displays decreased significantly in predator as compared to no-predator trials. Total number of sounds per contest dropped in parallel but no significant changes were observed in sound characteristics. In the presence of a predator dyadic contests were decided or terminated during lateral displays and never escalated to frontal displays. The gouramis showed approaching behaviour towards the predator between lateral displays. This is the first study supporting the hypothesis that predators reduce visual and acoustic signalling in a vocal fish. Sound properties, in contrast, did not change. Decreased signalling and the lack of escalating contests reduce the fish’s conspicuousness and thus predation threat.

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