breeding behaviour for carp and trout
Normal breeding behaviour for Carp.
Carp lay their eggs on vegetation. This is because they have a sticky texture and will stick to the vegetation. When seeing carp spawn, usually in the margins of the bank or an island, there will often be a few males for every female present, and they will thrash against the female, forcing the eggs out of the anus, as Carp are Oviparous, meaning that they lay their eggs, instead of live bearing the hatchlings. Once the eggs are forced out of the female, the male fish then have a small gap in which they release some of their milt, trying to fertilize the eggs. Abnormal breeding behaviour for Carp. When carp lay their eggs, they do so on vegetation, as their eggs are sticky. However if little or no eggs stick to the vegetation, this is abnormal, however can be down to lack of experience, especially if the fish is just becoming mature enough to produce and lay eggs. As with the males, they might not release sperm, which then won't fertilize the eggs, this as well is abnormal and could be a blockage, which could cause the fish ill-health. This is the same with the females, as they might struggle to lay their eggs, they could also have a blockage, which in a females case could result in death. Carp not laying their eggs on vegetation is very abnormal, if carp are seeing this it could be down to lack of experience, however there could also be a bad lack of vegetation around the lake, for the numbers of carp wanting to spawn. There has to be sufficient areas for spawning, and if no natural areas are supplied for carp, other attempts to encourage spawning, such as spawning brushes, and planting vegetation around the bank side should be made to ensure there are places for the carp to lay their eggs. |
Normal breeding behaviour for Trout.
As trout live in flowing river systems, their eggs have adapted to suit the particular environment. Gravel is the most common substrate on river beds in the UK. Trout eggs, as oppose to Carp eggs, aren't as sticky, therefore Trout do not lay their eggs on vegetation. With the fast flowing water, you'd probably think that Trout eggs would simply roll down stream with the flow and therefore not get fertilized. But as I said before Trout eggs have adapted, and are now an oval/egg shape. This is so the tiny eggs can slot into the gravelly substrate, and water can then easily pass over instead of carrying the eggs downstream. As with Carp, the female Trout will always be accompanied by a mature male Trout, as the eggs only have a small time after coming into contact with water, before becoming infertile. So usually the female would deposit her eggs at the same time as the male would release the milt. Abnormal breeding behaviour for Trout. Some less experienced Trout, may struggle to find the correct substrate in which she should lay her eggs, as I said this is just down to experience. Another abnormality when breeding would be for the Trout eggs to roll downstream and not slot into the gravel. This could be down to bad, unhealthy eggs with the wrong shape. The fish's diet can be a big part when creating the eggs and creating good healthy eggs, so the fish might not be getting the correct food or diet, which can result in poorly shaped eggs with no stickiness what so ever. If the female doesn't release her eggs, she might have a problem when releasing them. They could have a parasite infecting their gut, or could have a blockage within the fish's womb, for a female to keep her eggs in her body after spawning, without being able to release them, this can cause some serious health problems for the fish and could even result in mortalities. But also, would result in a bad breeding year for the river, and could see the rivers natural fish stocks deplete in the years ahead. |