Differential effects of turbidity on prey consumption of piscivorous and planktivorous fish

نویسندگان

  • Alex De Robertis
  • Clifford H. Ryer
  • Adriana Veloza
  • Richard D. Brodeur
چکیده

Contrast degradation theory predicts that increased turbidity decreases the visibility of objects that are visible at longer distances more than that of objects that are visible at short distances. Consequently, turbidity should disproportionately decrease feeding rates by piscivorous fish, which feed on larger and more visible prey than particle-feeding planktivorous fish. We tested this prediction in a series of laboratory feeding experiments, the results of which indicated that prey consumption by two species of planktivorous fish (juvenile chum salmon (Oncorhynchus keta) and walleye pollock (Theragra chalcogramma)) is much less sensitive to elevated turbidity than piscivorous feeding by sablefish (Anoplopoma fimbria). Planktivorous feeding in the turbidity range tested (0–40 nephelometric turbidity units (NTU)) was reduced at high light intensity, but not at low light intensity. Comparatively low (5–10 NTU) turbidity decreased both the rate at which sablefish pursued prey and the probability of successful prey capture. These results suggest that turbid environments may be advantageous for planktivorous fish because they will be less vulnerable to predation by piscivores, but will not experience a substantial decrease in their ability to capture zooplankton prey. Résumé : La théorie de la dégradation des contrastes prédit qu’une turbidité accrue décroît plus la visibilité d’objets qui sont visibles à de plus grandes distances que celle d’objets visibles à de courtes distances. En conséquence, la turbidité devrait faire décroître de façon disproportionnée les taux d’alimentation des poissons piscivores qui se nourrissent de proies plus grandes et plus visibles par comparaison aux taux d’alimentation des poissons planctonophages qui se nourrissent de particules. Une série d’expériences d’alimentation en laboratoire nous a permis de vérifier cette prédiction : la consommation de proies de deux espèces de poissons planctonophages, de jeunes saumons kéta (Oncorhynchus keta) et des goberges de l’Alaska (Theragra chalcogramma), est beaucoup moins affectée par une augmentation de la turbidité que la consommation de poissons par des morues charbonnières (Anoplopoma fimbria). Dans la gamme des turbidités étudiées (0–40 unités néphélométriques de turbidité, NTU), l’alimentation des planctonophages est réduite aux fortes intensités de lumière, mais non aux intensités faibles. Des turbidités relativement faibles (5– 10 NTU) entraînent une réduction du taux de poursuite ainsi que de la probabilité de capture des proies chez la morue charbonnière. Ces résultats semblent démontrer qu’un environnement turbide peut être avantageux pour les poissons planctonophages parce qu’ils y sont moins vulnérables à la prédation par les poissons piscivores, sans que leur capacité à capturer des proies zooplanctoniques ne soit substantiellement réduite. [Traduit par la Rédaction] De Robertis et al. 1526

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

The Effects of Turbidity on Prey Selection by Piscivorous Largemouth Bass

—Turbidity in aquatic systems can change rapidly, affecting the visual ability of predators. Increased turbidity is known to reduce the reactive distance and foraging success of some planktivores and insectivores, leading to decreased growth rates. However, little is known about the effects of turbidity on prey selection by piscivores. We examined the interactions between largemouth bass Microp...

متن کامل

Analysis of diet of piscivorous fishes in Bovan, Gruža and Šumarice reservoir, Serbia

Diet of adult pikeperch Sander lucioperca, Eurasian perch Perca fluviatilis, northern pike Esox lucius and European catfish Silurus glanis as top predators in aquatic ecosystems in Serbia was investigated during 2011, in order to understand their relationship to their prey and to investigate their food consumption, feeding and assimilation rate, cannibalism, and habitat segregation. Northern pi...

متن کامل

Analysis of diet of piscivorous fishes in Bovan, Gruža and Šumarice reservoir, Serbia

Diet of adult pikeperch Sander lucioperca, Eurasian perch Perca fluviatilis, northern pike Esox lucius and European catfish Silurus glanis as top predators in aquatic ecosystems in Serbia was investigated during 2011, in order to understand their relationship to their prey and to investigate their food consumption, feeding and assimilation rate, cannibalism, and habitat segregation. Northern pi...

متن کامل

Invertebrate predation and trophic cascades in a pe- lagic food web – The multiple roles of Chaoborus flavi- cans (Meigen) in a clay-turbid lake

Invertebrate predators often have dramatic effects on their prey communities. Unlike visually foraging planktivorous fish, invertebrate predators detect their prey by mechanoor chemoreception. Thus, fish and invertebrate predators affect zooplankton communities differently. Fish predation typically selects large cladocerans while invertebrate predators prefer prey of smaller size. Since inverte...

متن کامل

Seasonal effects of variable recruitment of a dominant piscivore on pelagic food web structure

Piscivorous fish play an important role in regulating lake food web structure. However, most ultimately piscivorous fish pass through a period of planktivory before becoming piscivorous. In 1993 and 1994, two large cohorts of young-of-the-year largemouth bass (Micropterus salmoides) were recorded in Paul Lake, Michigan. The 1993 and 1994 cohorts were the largest recorded in data extending back ...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2003