Feeding preference of adult females of ribbonfish Trichiurus lepturus through prey proximate-composition and caloric values

Abstract

In the present study we analysed the proximate-composition and caloric values of the preferred prey consumed by ribbonfish, Trichiurus lepturus L. 1758 (adult females), that are distributed in the inner continental shelf from northern Rio de Janeiro State, southeastern Brazil (~22ºS), assessing the potential of nutritional and energetic approach as a tool to understand the feeding selective pattern of this marine top carnivore. The preferred prey of this predator composed of fish co-specifics, Pellona harroweri, Chirocentrodon bleekerianus, Lycengraulis grossidens, Peprilus paru, squid Doryteuthis plei, and shrimp Xiphopenaeus kroyeri were collected from 2007 to 2010 for proximate-composition (water, protein, lipid, ash, and carbohydrate) and caloric value analyses. The correspondence analysis showed that protein is the main component in the prey species (61.32% of variance explained), standing out from the other nutrients. Lipid has the highest percentage related to L. grossidens, ash to X. kroyeri and carbohydrate to D. plei. The strong correlations between protein and caloric value (positive) and lipid and caloric value (negative) indicated that T. lepturus is attending its energy demand through the prey protein content. This work elucidated the feeding preference of adult females of T. lepturus in relation to nutritional and caloric content of their preferred prey. The species showed food selectivity to prey that provide more energy per ingested biomass, so that the feeding events can maximize the predator's caloric gain, which is obtained by a protein-based diet.No presente estudo foram analisadas a composição centesimal e o valor calórico das presas preferenciais consumidas pelo peixeespada, Trichiurus lepturus L. 1758 (fêmeas adultas), que se distribuem na plataforma continental interna do norte do estado do Rio de Janeiro, sudeste do Brasil (~ 22ºS). O objetivo foi avaliar o potencial da abordagem nutricional e energética como ferramenta para compreender o padrão de seletividade alimentar deste carnívoro marinho. As presas preferenciais deste predador, compostas por co-específicos e pelos peixes Pellona harroweri, Chirocentrodon bleekerianus, Lycengraulis grossidens e Peprilus paru, pela lula Doryteuthis plei e pelo camarão Xiphopenaeus kroyeri, foram coletadas entre 2007 e 2010 para análise da composição centesimal (água, proteína, lipídio, cinzas e carboidratos) e do valor calórico. A análise de correspondência mostrou que a proteína é o principal componente nas espécies de presa (61,32% da variância explicada), destacando-se dos outros nutrientes. Para o lipídio a maior porcentagem esteve relacionada com L. grossidens, cinzas com X. kroyeri e carboidratos com D. plei. As fortes correlações entre proteína e valor calórico (positiva) e lipídio e valor calórico (negativa) indicaram que T. lepturus está atendendo sua demanda de energia através do teor de proteína das presas. Este trabalho elucidou a preferência alimentar de fêmeas adultas de T. lepturus em relação ao conteúdo nutricional e calórico das pr...

Mercury and stable isotopes (δ15N and δ13C) as tracers during the ontogeny of Trichiurus lepturus

“…The same feeding habits all year could reflect the prey availability in the study area. As an adult, T. lepturus becomes a carnivorous fish that feeds preferentially on co-specifics, Pellona harroweri (teleost), Chirocentrodon bleekerianus (teleost), and Doryteuthis spp (squids) (Bittar et al, 2008;Bittar et al, 2012). These species are common in northern Rio de Janeiro all year round and are available to the local marine top predators (Di Beneditto & Ramos, 2001;Di Beneditto & Ramos, 2004;Bittar et al, 2008).…”

Changes in the diet of predatory ribbonfish Trichiurus lepturus Linnaeus, 1758 with increasing body size along Chennai coast

“…Prey selectivity is based on availability and size of prey as well as energy/ protein content of prey. T. lepturus in the inner continental shelf of south-east Brazil selected prey that provided more energy per ingested biomass, so that the feeding events maximised the predator's caloric gain (Bittar et al, 2012).…”

“…However, the capacity to hold the prey in the gut is limited beyond 800 mm length of the ribbonfish. Several researchers on ribbonfishes have reported dietary shift from zooplanktivore feeder at juvenile stage to voracious carnivore at adult stage (for example, Bakhoum, 2007;Bittar et al, 2012;Yan et al, 2012).…”

Mercury bioaccumulation and isotopic relation between Trichiurus lepturus (Teleostei) and its preferred prey in coastal waters of southeastern Brazil

“…These specimens were targets of local commercial fisheries. The preferred prey were collected in the same area during local commercial fi sheries (target or by-catch species), taking into account the prey size consumed by the predator (see Bittar et al 2008Bittar et al , 2012. A sample from the back dorso-lateral muscle (fi sh), mantle (squid), or abdomen (shrimp) removed from each specimen (predator and prey) was freeze-dried and homogenized with a mortar and pestle for total mercury and stable isotopes analyses.…”

“…During its ontogeny, there is a wide diet shift: juveniles are planktivores, while adults are top predators, feeding on the most abundant prey. In coastal waters of southeastern Brazil (~21-22°S), the feeding habits of adult specimens of T. lepturus was detailed by Bittar et al (2008Bittar et al ( , 2012. Twelve-eight prey species were recorded for this predator, and seven were the most representative in its diet, in this order: juvenile conspecifi cs, which represented 33% of the diet; Pellona harroweri Fowler, 1917 (17%); Dorytheuthis plei Blainville, 1823 (13%); Chirocentrodon bleekerianus Poey, 1867 (11%); Xiphopenaeus kroyeri Heller, 1862 (11%); Lycengraulis grossidens Spix & Agassiz, 1829 (6%); and Peprilus paru Linnaeus, 1758 (3%).…”