Stickleback. (Gasterosteus aculeatus)
Sticklebacks are small, bony fish that exist throughout most of the world and are known to have a wide variety of subspecies, (for example Gasterosteus aculeatus williamsoni) that have phenotypically adapted to various environmental factors. They are small fish (2-4 inches) and are characterized by a row of free dorsal fins in front of the dorsal fin combined with the absence of scales.
Male sticklebacks build intricate golf ball-sized nests, which he guards aggressively. Both males and females come together for a mating rituals. Breeding typically starts between the second and third year in the spring and summer. Males start to develop a deep red coloration on their throats and a blue tint in the eyes. They establish their territories by chasing other rival males away from their nesting site. Receptive females are led back to the nest where she deposits her eggs. The eggs are immediately fertilized by the male who then chases the female away. The eggs are protected by the male from predators and other males.
Proteocephalus is a cestode parasite, a tapeworm wtih four suckers and no hooks. The eggs are shed from the posterior segments and passed out in the faeces. The first intermediate host is a copeod such as a Cyclops which eat the eggs. The eggs then hatch in the intestine and the larva burrow into the body cavity and a procercoid develops. The second intermediate host is the stickleback which eats the copeod and the larva attaches to the intestine wall and develops here. The fish becomes infected directly after consuming them.
Sticklebacks are small, bony fish that exist throughout most of the world and are known to have a wide variety of subspecies, (for example Gasterosteus aculeatus williamsoni) that have phenotypically adapted to various environmental factors. They are small fish (2-4 inches) and are characterized by a row of free dorsal fins in front of the dorsal fin combined with the absence of scales.
Male sticklebacks build intricate golf ball-sized nests, which he guards aggressively. Both males and females come together for a mating rituals. Breeding typically starts between the second and third year in the spring and summer. Males start to develop a deep red coloration on their throats and a blue tint in the eyes. They establish their territories by chasing other rival males away from their nesting site. Receptive females are led back to the nest where she deposits her eggs. The eggs are immediately fertilized by the male who then chases the female away. The eggs are protected by the male from predators and other males.
Proteocephalus is a cestode parasite, a tapeworm wtih four suckers and no hooks. The eggs are shed from the posterior segments and passed out in the faeces. The first intermediate host is a copeod such as a Cyclops which eat the eggs. The eggs then hatch in the intestine and the larva burrow into the body cavity and a procercoid develops. The second intermediate host is the stickleback which eats the copeod and the larva attaches to the intestine wall and develops here. The fish becomes infected directly after consuming them.
