e-journal

The morphology–diet relationship and its role in the coexistence of two species of annual fishes

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Annual fishes, which inhabit temporary pools with extremely limited habitat complexity and niche
availability, display remarkable sexual dimorphism, rapid growth, and enormous investment into reproduction, all traits associated with high energy requirement. This study tests three hypotheses for two syntopic annual fishes (Austrolebias minuano and Cynopoecilus fulgens) found in six wetlands of southern Brazil: (i) considerable morphological differences result in low dietary overlap, (ii) sexual dimorphism in both species leads to intraspecific diet segregation, and (iii) dietary richness increases during ontogenetic development, and is narrower in C. fulgens than A. minuano due to morphological limitations imposed by reduced size. The diet of 82 A. minuano and 211 C. fulgens individuals was analyzed over two annual cycles. The morphology was characterized by 26 measurements covering the entire body of both species. There was no evidence of morphological specialization related to food competition and the diet of A. minuano and C. fulgens showed high overlap. High food availability, high predator abundance, and high connectivity of adjacent wetlands are likely the main mechanisms allowing coexistence of both species. Within species, sexual dimorphism did not result in a decrease in dietary overlap, which reinforces the idea that morphological differences between the sexes did not evolve as a mechanism to decrease food competition. Large A. minuano did not have a more diverse diet than the smaller C. fulgens; however, increase in body size allowed both species to ingest larger prey. Morphological variability in both species was mainly related to ontogenetic development and reproduction.

Key words: Austrolebias minuano; Cynopoecilus fulgens; niche overlap; sexual dimorphism; ontogeny

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Ketersediaan

Tidak ada salinan data

Informasi Detail

Judul Seri

Ecology of Freshwater Fish

No. Panggil

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Penerbit

Brazil : John Wiley & Sons Ltd., 2014

Deskripsi Fisik

Ecology of Freshwater Fish 2015: 24: 77–90

Bahasa

English

ISBN/ISSN

doi: 10.1111/eff.121

Klasifikasi

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Tipe Isi

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Tipe Media

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Tipe Pembawa

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Edisi

2015: 24: 77–90

Subjek

PERIKANAN

Info Detail Spesifik

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Pernyataan Tanggungjawab

Mutia/Agus

Versi lain/terkait

Lampiran Berkas

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