Vision is not necessary for size-selective zooplanktivory in aquatic salamanders

Abstract

LANNOO, M. J. 1986. Vision is not necessary for size-selective zooplanktivory in aquatic salamanders. Can. J. Zool. 64: 1071-1075. Vision is usually implicated as the sensory modality employed in size-selective zooplanktivory by aquatic vertebrates. I tested this generalization for nocturnally active salamanders by offering sighted and enucleated Ambystoma maculatum larvae a choice of large vs. small, or normally coloured vs. artificially darkened Daphnia, a natural prey. Salamanders in all treatments took the largest Daphnia and exhibited similar high feeding rates. There was no preference for artificially darkened Daphnia, as would be expected if visual cues predominate. Together these results indicate that vision is not exclusively responsible for size-selective predation by nocturnal salamanders. The often stated or implied assumption that size selectivity indicates visual predation in aquatic vertebrates should thus be questioned.LANNOO, M. J. 1986. Vision is not necessary for size-selective zooplanktivory in aquatic salamanders. Can. J. Zool. 64: 1071-1075. Les vertkbrks aquatiques utilisent ordinairement leur sens de la vue pour choisir des proies en fonction de la taille dans le zooplancton. J'ai mis cette thkorie ii l'kpreuve chez des salamandres actives la nuit, en offrant un choix de petites ou de grosses proies ou un choix Daphnia, une proie naturelle, de couleurs normales ou de Daphnia colorkes artificiellement ii des larves rendues aveugles et des larves intactes d' Ambystoma maculatum. Dans toutes les exNriences, les salamandres ont choisi les plus grosses daphnies et leur taux d'alimentation s'est avCrC semblable et ClevC dans tous les cas. I1 n' y avait pas de prkfkrence pour les daphnies plus foncCes colorkes artificiellement c o m e on devrait s'y attendre si les salamandres chassaient ii vue. Ces rksultats indiquent donc que la vision n'est pas exclusivement responsable de la prkdation en fonction de la taille chez les salamandres nocturnes. La thCorie souvent invoquCe selon laquelle la sklectivitC des proies suppose une prkdation par chasse ii vue chez les vertkbrks aquatiques est remise en question.[Traduit par la revue]

Diet of feralXenopus laevis(Daudin) in South Wales, U.K.

“…For most items of terrestrial origin, prey may have been detected visually (Measey, 1998), or by detection of waves in the surface tension (Elepfandt, 1996). Lannoo (1986) found that vision was not necessary for Ambystoma maculatum (Shaw) larvae to be size-selective in their predation of zooplankton. Activity of X. laevis is known to be crepuscular and nocturnal (see , which corresponds to high activity levels of some of their most important prey (Hershey, 1987).…”

Diet of feral Xenopus laevis (Daudin) in South Wales, U.K.

“…Activity of X. laevis is known to be crepuscular and nocturnal (see , which corresponds to high activity levels of some of their most important prey (Hershey, 1987). Lannoo (1986) found that vision was not necessary for Ambystoma maculatum (Shaw) larvae to be size-selective in their predation of zooplankton. He further suggested that lateral line organs may be primarily responsible for zooplanktivory in enucleated salamander larvae.…”

Alpine newts (Triturus alpestris) as top predators in a high‐altitude karst lake: daily food consumption and impact on the copepod Arctodiaptomus alpinus

“…The sensory abilities for prey detection and evaluation are highly evolved in larval and adult urodeles (Himstedt, 1967;Joly, 1981Joly, ,1982Lannoo 1986); not only are optical and chemical cues important but mechanical and electroreceptive cues (Fritzsch & Wahnschaffe, 1983) also trigger prey capture and allow feeding during the night.…”