Comportamento de Litopenaeus vannamei (Boone) (Crustacea, Decapoda, Penaeidae) em função da oferta do alimento artificial nas fases clara e escura do período de 24 horas

Medeiros

Marine and Freshwater Behaviour and Physiology

et al. 2012

This study characterized a number of the behaviors of Farfantepenaeus subtilis in response to the offer of feed at different times during a 24 h cycle. Shrimp were observed under laboratory conditions during 12 h light-12 h dark cycles, before and immediately after feeding. The behaviors recorded were: burrowing, substrate exploration, vertical exploration, ingestion, swimming, inactivity, and crawling. The frequencies of all these behaviors increased in the presence of food, independent of time or light phase. The consumption of feed was more frequent in the morning. The results showed that the rhythm of activity is influenced by the light-dark cycle and the availability of food. The results are different from those reported for other shrimp species and indicate the potential value of understanding the behavioral details of each species for optimizing their management.

Section: Discussionmentioning

confidence: 88%

A study of feeding in the shrimpFarfantepenaeus subtilisindicates the value of species level behavioral data for optimizing culture management

Medeiros

Marine and Freshwater Behaviour and Physiology

et al. 2012

“…Para a observação na fase clara, os tanques foram submetidos à iluminação natural. Na fase escura, os tanques foram observados com o auxílio de lâmpada incandescente vermelha (15 watts, que geraram um lux), em razão da não reatividade dos camarões a esse tipo de luminosidade (Pontes & Arruda, 2005).…”

Section: Methodsunclassified

Comportamento do camarão em diferentes substratos nas fases clara e escura do dia

Santos

Freire

Pontes³

2013

Pesq. agropec. bras.

Resumo -O objetivo deste trabalho foi avaliar o efeito do tipo de substrato sobre a preferência, o enterramento e a atividade natatória de camarões (Litopenaeus vannamei). Juvenis (0,93±0,29 g) e adultos machos e fêmeas (10,05±1,18 g) foram observados durante 24 horas, por meio do método animal focal, com registros instantâneos. Foram testadas as seguintes granulometrias (tratamentos) dos substratos: I, 100% C; II, 50% C + 50% B; III, 50% A + 50% C; IV, 100% B; V, 50% B + 50% A; e VI, 100% A, em que as letras referemse ao diâmetro médio das partículas, A = 0,25-2,0 mm; B = 0,0625-0,25 mm; e C = <0,0625 mm. Foram aplicados seis tratamentos com 18 repetições para cada categoria: camarões juvenis, machos e fêmeas. Cada indivíduo foi exposto por 24 horas aos seis tipos de substrato, simultaneamente, e o seu comportamento foi observado nas fases clara e escura do dia. A natação ocorreu principalmente na fase escura e o enterramento, na fase clara, no substrato IV. Os camarões juvenis e adultos (machos ou fêmeas) preferem o substrato composto de areia fina e muito fina (0,0625-0,25 mm), tanto para permanência quanto para enterramento.Termos para indexação: Litopenaeus vannamei, bem-estar animal, carcinicultura, etologia aplicada. Shrimp behavior in different substrates in light and dark phases of the dayAbstract -The objective of this work was to evaluate the effect of substrate type on the preference, burial, and natatory activity of shrimp (Litopenaeus vannamei). Juvenile (0.93±0.29 g) and adult males and females (10.05±1.18 g) were observed during 24 hours using the focal animal method, with instantaneous recording. The following soil granulometries (treatments) were tested: I, 100% C; II, 50% C + 50% B; III, 50% A + 50% C; IV, 100% B; V, 50% B + 50% A; and VI, 100% A, in which the letters reffer to particle mean diameter, A = 0.25-2.0 mm, B = 0.0625-0.25 mm, and C = <0.0625 mm. Six treatments were applied with 18 replicates for each category: juvenile, male, and female shrimp. Each individual was simultaneously exposed for 24 hours to the six types of substrates, and its behavior was observed in the light and dark phases of the day. Swimming occurred mainly during the dark phase, and burial in the light phase in substrate IV. The juvenile and adult shrimp (male or female) prefer substrate composed of fine and very fine sand (0.0625-0.25 mm), both for residence and for burial.

“…This pattern is similar to other decapod species from inland waters, which indicates a crepuscular (dawn and dusk) feeding rhythm (Collins 1997;Williner and Collins 2002;Aguzzi et al 2005;Zimmermann et al 2009). However, there are many evidences that the presence of food at any time of the day can trigger the locomotion in decapod crustaceans even in periods of low activity (Fernandez de Miguel and Aréchiga 1994;Reigada 2002;Pontes and Arruda 2005;Sokolowicz et al 2007;Zimmermann et al 2009). Indeed, in T. kensleyi, the presence of prey items in the gut content suggests a continuous food intake and can provide clues of the movement of crabs in streams throughout the day.…”

Section: Naupliimentioning

confidence: 99%

Feeding spectra and activity of the freshwater crab Trichodactylus kensleyi (Decapoda: Brachyura: Trichodactylidae) at La Plata basin

2014

Background: In inland water systems, it is important to characterize the trophic links in order to identify the 'trophic species' and, from the studies of functional diversity, understand the dynamics of matter and energy in these environments. The aim of this study is to analyze the natural diet of Trichodactylus kensleyi of subtropical rainforest streams and corroborate the temporal variation in the trophic activity during day hours. Results: A total of 15 major taxonomic groups were recognized in gut contents. The index of relative importance identified the following main prey items in decreasing order of importance: vegetal remains, oligochaetes, chironomid larvae, and algae. A significant difference was found in the amount of full stomachs during day hours showing a less trophic activity at midday and afternoon. The index of relative importance values evidenced the consumption of different prey according to day moments. Results of the gut content indicate that T. kensleyi is an omnivorous crab like other trichodactylid species. Opportunistic behavior is revealed by the ingestion of organisms abundant in streams such as oligochaetes and chironomid larvae. The consumption of allochthonous plant debris shows the importance of this crab as shredder in subtropical streams. However, the effective assimilation of plant matter is yet unknown in trichodactylid crabs. Conclusions: This research provides knowledge that complements previous studies about trophic relationships of trichodactylid crabs and supported the importance of T. kensleyi in the transference of energy and matter from benthic community and riparian sources to superior trophic levels using both macro-and microfauna.