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Howard I. BROWMAN
BROWMAN, H.I., J. YEN, D.M. FIELDS, J.-F. ST-PIERRE, A.B. SKIFTESVIK, 2011. Fine-scale observations of the predatory behaviour of the carnivorous copepod Paraeuchaeta norvegica and the escape responses of their ichthyoplankton prey, Atlantic Cod (Gadus morhua). Mar. Biol., 158(12): 2653-2660 .
Paraeuchaeta norvegica (8.5 mm total length) and yolk-sac stage Atlantic cod larvae (4 mm total length) (Gadus morhua) larvae were observed in aquaria (3 l of water) using silhouette video photography. This allowed direct observations (and quantitative measurement) of predatorprey interactions between these two species in 3-dimensions. Tail beats, used by cod larvae to propel themselves through the viscous fluid environment, also generate signals detectable by mechanoreceptive copepod predators. When the prey is close enough for detection and successful capture (approximately half a body-length), the copepod launches an extremely rapid high Reynolds number attack, grabbing the larva around its midsection. While capture itself takes place in milliseconds, minutes are required to subdue and completely ingest a cod larva. The behavioural observations are used to estimate the hydrodynamic signal strength of the cod larvas tail beats and the copepods perceptive field for larval fish prey. Cod larvae are more sensitive to fluid velocity than P. norvegica and also appear capable of distinguishing between the signal generated by a swimming and an attacking copepod. However, the copepod can lunge at much faster velocities than a yolk-sac cod larva can escape, leading to the larvas capture. These observations can serve as input to the predator–prey component of ecosystem models intended to assess the impact of P. norvegica on cod larvae.©2011 Springer
BROWMAN, H.I., J.-F. ST-PIERRE, A.B. SKIFTESVIK, R.G. RACCA, 2003. Behaviour of Atlantic cod (Gadus morhua) larvae : an attempt to link maternal condition with larval quality. Pages 72-95 in H.I. Browman, J.-F. St-Pierre, A.B. Skiftesvik & R.G. Racca. Behaviour of Atlantic cod (Gadus morhua) larvae: an attempt to link maternal condition with larval quality. The Big Fish Bang. .
BROWMAN, H.I., J.-F. ST-PIERRE, P. KUHN, 2003. Dose and dose-rate dependency in the mortality response of Calanus finmarchicus embryos exposed to ultraviolet radiation. Mar. Ecol. Prog. Ser., 247: 297-302 .
BROWMAN, H.I., R.D. VETTER, C.A. RODRIGUEZ, J.J. CULLEN, R.F. DAVIS, E. LYNN, J.-F. ST-PIERRE, 2003. Ultraviolet (280-400 nm)-induced DNA damage in the eggs and larvae of Calanus finmarchicus G. (Copepoda) and Atlantic Cod (Gadus morhua). Photochem. Photobiol., 77(4): 397-404 .
NOVALES FLAMARIQUE, I., H.I. BROWMAN, 2001. Foraging and prey-search behaviour of small juvenile rainbow trout (Oncorhynchus mykiss) under polarized light. J. Exp. Biol., 204(14): 2415-2422 .
RODRIGUEZ, C.A., H.I. BROWMAN, J.-F. ST-PIERRE, 2000. High survival of neustonic zoea I larvae of American lobster Homarus americanus following short-term exposure to ultraviolet (280 to 400 nm). Mar. Ecol. Prog. Ser., 193: 305-309 .
BROWMAN, H.I., C.A.RODRIGUEZ, F. BÉLAND, J.J. CULLEN, R.F. DAVIS, J.H.M. KOUWENBERG, P.S. KUHN, B. McARTHUR, J.A. RUNGE, J.-F. ST-PIERRE, R.D. VETTER, 2000. Impact of ultraviolet radiation on marine crustacean zooplancton and ichthyoplankton : a synthesis of results from the estuary and Gulf of St. Lawrence, Canada. Mar. Ecol. Prog. Ser., 199: 293-311 .
KUHN, P.S., H.I. BROWMAN, R.F. DAVIS, J.J. CULLEN, B.L. McARTHUR, 2000. Modeling the effects of ultraviolet radiation on embryos of Calanus finmarchicus and Atlantic cod (Gadus morhua) in a mixing environment. Limnol. Oceanogr., 45:1797-1806 .
BÉLAND, F., H.I. BROWMAN, C.A. RODRIGUEZ, J.-F. ST-PIERRE, 1999. Effect of solar ultraviolet radiation (280-400 nm) on the eggs and larvae of Atlantic cod (Gadus morhua). Can. J. Fish. Aquat. Sci., 56: 1058-1067 .
In the Gulf of St. Lawrence, Canada, solar ultraviolet B radiation (UV-B, 280-320 nm) penetrates a significant percentage of the summer mixed-layer water column : organisms residing in this layer : such as the eggs of Atlantic cod (Gadus morhua), are exposed to UV-B. IN outdoor exposure experiments, Atlantic cod eggs were incubated in the presence versus the absence of UV-B and (or) UV-A (320-400 nm). We tested two hypotheses : H1, UV-B induces mortality in Atlantic cod eggs, and H2, UV-A either exacerbates or mitigates any such UV-B-induced mortality. Hypothesis H1 was supported : there was a significant mortality effect on Atlantic cod eggs exposed to UV-B at the surface and at a depth of 50 cm. Hypothesis H2 was not supported : there was no effect of UV-A. These experiments indicate that Atlantic cod eggs present in the first metre ot fhe water column (likely only a small percentage of the total egg population) are susceptible to UV-B. However, UV-B must be viewed as only one among many environmental factors that produce the very high levels of mortality typically observed in the planktonic early life stages of marine fishes.
DUTIL, J.-D., M. CASTONGUAY, M.O. HAMMILL, P. OUELLET, Y. LAMBERT, D. CHABOT, H. BROWMAN, D. GILBERT, A. FRÉCHET, J.-A. GAGNÉ, D. GASCON, L. SAVARD, 1998. Environmental influences on the productivity of cod stocks : some evidence for the northern Gulf of St. Lawrence, and required changes in management practices. DFO, Canadian Stock Assessment Secretariat, Research Document, 98/18, 42 p .
VAUGHAN, H., J. CAREY, B. BUKATA, H. BROWMAN, M. MORRISON, K. PERCY, R. ROBARTS, F. CRISP, 1997. Addressing the ecosystem effects of ultraviolet radiation : including an inventory of research and collaborative mechanisms in Canada. Burlington, Ontario, National Water Research Institute, Aquatic Ecosystem Conservation Branch .
BROWMAN, H.I., A.B. SKIFTESVIK, R. RACCA, 1996. Turbulence and ichthyoplankton-zooplankton interactions : a sensitivity analysis and critique of the assumptions underlying the behavioural components of analytical models. 76th Annual Meeting of the American Society of Ichthyologists and Herpetologists, New Orleans, LA (USA), Jun 13-19 .
BROWMAN, H.I., 1996. L'augmentation du rayonnement ultraviolet B peut-elle avoir des incidences négatives sur les ressources marines dans le golfe du Saint-Laurent. Naturaliste can., 120(2): 66-68 .
BROWMAN, H.I., A.B. SKIFTESVIK, 1996. Effects of turbulence on the predation cycle of fish larvae : comments on some of the issues. Mar. Ecol. Prog. Ser., 139: 309-312 .
BROWMAN, H.I., 1996. Predator-prey interactions in the sea : commentaries on the role of turbulence. Mar. Ecol. Prog. Ser., 139: 301-302 .
BROWMAN, H.I., 1995. Introduction : commentaries on current research trends in recruitment studies. Mar. Ecol. Prog. Ser., 128: 305 .
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