Response of the eastern rainbowfish (Melanotaenia duboulayi) to toxic Microcystis aeruginosa

Abstract

Eastern rainbowfish (Melanotaenia duboulayi) were exposed to lysed cell suspensions of toxic Microcystis aeruginosa. Fish ventilatory behaviour was monitored with a computerized biomonitoring system. At its operational settings, the biomonitor did not detect a significant ventilatory response in the test fish when they were exposed to microcystin concentrations between 1.6 × 10-3 and 2.6�g mL-1 microcystin-LR equivalent. These results suggested that the fish respiratory system is unaffected by short-term exposure to microcystin or other biologically active compounds produced by M. aeruginosa.

The Effects of Harmful Algal Blooms on Aquatic Organisms

“…Fish have been experimentally exposed to microcystins via a number of routes, including intraperitoneal injection, oral ingestion (fed ad libitum or by gavage), and bath immersion (Phillips et al, 1985;Sugaya et al, 1990;Råbergh et al, 1991;Andersen et al, 1993;Johnston et al, 1994;Keshavanath et al, 1994;Tencalla et al, 1994;Williams et al, 1995Williams et al, , 1997bCarbis et al, 1996aCarbis et al, , 1996bKotak et al, 1996a;Sahin et al, 1996;Bury et al, 1997Bury et al, , 1998aBury et al, , 1998b. In general, fish are insensitive to short-term immersion in toxic microcystin solutions (Phillips et al, 1985;Sugaya et al, 1990;Johnston et al, 1994;Tencalla et al, 1994;Bury et al, 1995). When exposed to freeze-dried toxic Microcystis in water, rainbow trout, Oncorhynchus mykiss, did not die and showed no significant clinical or histological changes over a 96-h period (Tencalla et al, 1994).…”

Outcomes of Repeated Exposure of the Carp (Cyprinus carpio L.) to Cyanobacteria Extract

“…Their cancerogenic effects were also documented (Bell and Codd 1994). The influence of cyanotoxins on fish has been studied by a number of authors using clinical, pathomorphological, histological, ultrastructural, haematological and biochemical methods (Bruno et al 1989;R åbergh et al 1991;Johnston et al 1994;Rodger et al 1994;Tencalla et al 1994;Carbis et al 1996aCarbis et al , 1996bCarbis et al , 1997Bury et al 1997;Palíková et al 1998;V a j cová et al 1998;N avrátil et al 1998;Kopp and Hete‰a 2000).…”

Behavioural and physiological effects of methadone in the perioperative period on the Nile tilapia Oreochromis niloticus

“…The videos (5 min each) were recorded before anaesthesia induction and at 1, 2, 3, 6, 12 and 24 h after moving the fish to the recovery tank. At these intervals, the opercular beat rate, caudal‐fin beat rate and use of cover (percentage of time spent undercover; Johnston et al, ; Sneddon, ; Reilly et al, ) were recorded. The recovery time, i.e.…”

“…Induction times were 439.4 ± 179 s and 338.3 ± 110 s for CG and MG, respectively ( t = 1.19, df = 11, P > 0.05). Individuals were considered anaesthetised when lying down at the bottom of the tank, which was confirmed by a lack of response to a firm squeeze at the base of the tail (Johnston et al, ; Sneddon, ; Gressler et al, ). The basal and post‐induction ventilation rate, post‐induction and post‐surgery heart rate, time to resume spontaneous ventilation and recovery times are given in Table .…”