The histopathology of carp, Cyprinus carpio L., exposed to microcystins by gavage, immersion and intraperitoneal administration

Abstract

Carp liver, gills, intestine, kidneys, heart and spleen were studied by histology after the fish were exposed to microcystins by gavage, immersion and intraperitoneal administration, Intraperitoneal inoculation with microcystins caused necrosis or dosedependent degeneration in the liver, gills and kidneys. Gavaging v^^ith microcystins caused changes in the histopathology of the liver and gills. Cellular degeneration and necrosis occurred in the liver, gills and kidneys when carp were introduced to a tank containing 1-7 fJ% ml"' of microcystins. Lesions were not observed in the heart, spleen or intestines from atiy of the treated catp. Microcystins adtninistered by intraperitoneal injection at a concentration of 50 (^ kg"' were lethal to all fish within 8 h, while gavaging with 250 /^ kg"' of microcystins caused minimal damage in the tissues studied.

Effect of dietary cyanobacteria on growth and accumulation of microcystins in Nile tilapia (Oreochromis niloticus)

“…Normally, toxic effect of oral administration is approximately 10 times lower than that of intraperitoneal application (Carbis et al, 1996). In the present experiment, the dietary intake of microcystins by tilapia was 1500-6000 μg/kg body weight and it could show the similar impact on fish as 150-600 μg/kg body weight through intraperitoneal injection.…”

“…Fish mortality was reported to be associated with toxic cyanobacterial water blooms (Andersen et al, 1993;Rodger et al, 1994;Tencalla et al, 1994;Zimba et al, 2001). The acute effects on fish exposed to M. aeruginosa or microcystin have been confirmed (Carbis et al, 1996;Bury et al, 1997). But in most situations, the impacts of toxic cyanobacteria on fish could be at sublethal or chronic levels.…”

Oral toxicity of the microcystin-containing cyanobacterium Planktothrix rubescens in European whitefish (Coregonus lavaretus)

“…The LD 50 value for orally applied MC-LR to carp was reported to be <1.7 mg/kg body weight (Tencalla, 1995), while the LD 50 for orally applied MC-LR to trout was found to range between 1.7 and 6.6 mg/kg body weight (Tencalla et al, 1994). Similar species differences were demonstrated for intraperitoneally applied MC-LR (Råbergh et al, 1991;Tencalla et al, 1994;Carbis et al, 1996). The observed species-specific sensitivities to microcystins have been interpreted as resulting from anatomical, physiological and behavioural differences amongst the various fish orders (Tencalla, 1995;.…”

Response and recovery of hybrid sturgeon from subchronic oral administration of cyanobacteria

“…However, the harmful effects of MCs on fishes were mainly limited to acute toxic exposure routes and they were based on either oral gavaging, or intraperitoneal injection, or administration via the dorsal aorta of the toxins (Carbis et al, 1996;Bury et al, 1997;Li et al, 2005), which cannot reflect the uptake route under natural environments. More importantly, cyanobacteria are an important dietary component for many fish species (e.g., Tilapia) (Zurawell et al, 2005).…”