Feeding preferences of the sandhopper Orchestoidea tuberculata: the importance of algal traits

Abstract

Factors such as nutritional quality and the secondary metabolite content of food resources have been shown to influence the feeding behavior of herbivores in many marine habitats. For intertidal macroalgae consumers on sandy beaches, the influence of these factors on feeding behavior and the consequences on their performance is poorly understood. In this study, we evaluated the relationships of nutritional quality, chemical defenses (phlorotannins), and the structure of three macroalgal species that form the bulk of imported wrack subsidies to beaches in southern Chile, with the feeding behavior, absorption efficiency, and growth rate of the talitrid amphipod Orchestoidea tuberculata, one of the most abundant organisms in this environment. The amphipods preferred Durvillaea antarctica over Lessonia nigrescens and Macrocystis pyrifera when simultaneously offered fresh pieces of each alga. Similar results were observed when artificial food made of dry powdered algae of each species was provided, suggesting that the structure of these three algae did not influence preference. The performance of amphipods when reared on a diet of a single algal species matched feeding preferences; higher growth rates were observed in treatments with the preferred alga, D. antarctica. These results imply that D. antarctica is a superior food item for O. tuberculata when compared to L. nigrescens or M. pyrifera, and also that the alga's intrinsic quality (i.e., not structure) may influence dietary preference in these consumers. The higher content of proteins and carbohydrates found in D. antarctica may explain why this macroalga represents better quality food for O. tuberculata. Phlorotannin content did not have obvious negative effects on diet choice or growth, as D. antarctica, the alga with greater content of these secondary metabolites, was preferred and associated with higher growth rates of O. tuberculata. However, it is necessary to emphasize that the low phlorotannins concentrations registered in the three macroalgae species examined in this study, may not have been sufficient to deter O. tuberculata. When the amphipods were fed with each alga individually, they consumed significantly higher quantities of D. antarctica, which suggests that O. tuberculata did not eat more to compensate for the lower nutritional quality of the other algal species in order to maintain growth. Nor was compensation for lower food quality achieved by increasing absorption efficiency. Our results imply that the composition of the macroalgae arriving on the beach can significantly affect the performance and subsequent life history traits of O. tuberculata and by extension other amphipod species.

Utilization of different macroalgae by sea cucumber Apostichopus japonicus revealed by carbon stable isotope analysis

“…The selective utilization among various basal food resources can be attributed to nutritional quality and the potential availability of different food sources (Boettcher & Targett 1993, Jormalainen et al 2005, Rodil et al 2008, Duarte et al 2010, Seymour et al 2013. In the present study, U. lactuca had lower C/N ratios compared with S. muticum or G. lemaneiformis, indicating the relatively high food availability of U. lactuca for A. japonicus, as organic nitrogen is more readily utilized than organic carbon (Danovaro et al 2001).…”

“…Different basal food resources, e.g. brown, red and green algae, generally have distinctive biochemical compositions and consequently different nutritional values and food quality, which could po tentially influence the feeding selectivity of consumers (Danovaro et al 2001, Adin & Riera 2003, Jormalainen et al 2005, Rodil et al 2008, Duarte et al 2010. Although the biology of A. japonicus has been studied for several decades, research efforts on the feeding habits and food preferences are relatively scarce to date (Gao et al 2011, Sun et al 2013.…”

Niche segregation amongst sympatric species at exposed sandy shores with contrasting wrack availabilities illustrated by stable isotopic analysis

“…Adin and Riera, 2003;Crawley and Hyndes, 2007;Duarte et al, 2010;Poore and Gallagher, 2012), however, Rossi et al (2010) described an opportunistic behaviour for amphipods that relied on seagrasses (Sargassum muticum) when this resource was deposited in large quantities on the shore, and Porri et al (2011) found an ephemeral relationship between amphipods and specific wrack subsidies in South Africa. Herein, we also describe an opportunistic feeding behaviour, mainly of the consumers at Cabedelo beach, which might utilise the various sources indiscriminately as a result of the higher availability of wrack deposited on the shore.…”

“…Colombini et al, 2000;Duong and Fairweather, 2010;MacMillan and Quijón, 2012;Olabarria et al, 2007). The dietary wrack preferences of particular taxa (mainly amphipods) were also extensively studied, and while some studies showed similarly strong preferences for the brown algae (Adin and Riera, 2003;Crawley and Hyndes, 2007;Duarte et al, 2010;Olabarria et al, 2009), others showed that they are indiscriminate feeders (McLeod et al, 2013) and even not related with specific wrack species (Colombini et al, 2009;Porri et al, 2011).…”

Protocolos para o monitoramento de habitats bentônicos costeiros - Rede de Monitoramento de Habitat Bentônicos Costeiros - ReBentos

“…As características morfodinâmicas das praias onde foram realizados estudos de distribuição e ciclo de vida dessa espécie são do tipo dissipativo, de declive suave e granulometria fina com elevado aporte de algas arribadas. Talorchestia tucurauna apresenta um comportamento semelhante às demais espécies presentes em regiões temperadas e subtropicais como Talitrus saltador (Montagu, 1808), Bollorchestia quoyana (Milne-Edwards, 1840) e Orchestoidea tuberculata Nicolet, 1849 (Mardsen, 1991;Scapini et al, 1992;Duarte et al, 2010) que utilizam as algas arribadas como abrigo e alimento. Geralmente, as espécies associadas ao detrito vegetal estão localizadas na região superior do entremarés e no supralitoral, formando densas agregações embaixo das manchas de algas.…”