I don’t understand how a fish can get into a lake. eli5

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This is a example of a lake called Dayang bunting lake in my home country of Malaysia. It’s like a lake in an island surrounded by water. The origin is like a limestone place collapsed and rainfall collected creating a humongous lake. The surroundings are very high and unlikely to flood over. And there’s like fish in the lake. How did the fish get in there. With no input of water into the lake

In: Biology

11 Answers

Anonymous 0 Comments

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Anonymous 0 Comments

Most natural lakes are connected to other waterways at some point in their history, either when they’re initially formed, or during freak weather events that lead to flooding.

Something like a former quarry that slowly fills with rainwater could either have humans release types of fish they want to eat, an inflow of water during a temporary event allowing fish to migrate, etc.

For the specific lake you mentioned, the most common explanation is that people brought fish to the lake and releases them there to catch later.

Anonymous 0 Comments

There are lots of ways.

1: If there was a body of water there in the not too distant past and a cycle of flooding and drying is expected, several species of fish will either burrow into the ground or lay eggs in the mud to lay dormant until seasonal flooding. Probably not relevant in your case but worth pointing out

2: Birds of Prey: Say a predatory bird grabs a fish carrying eggs, and accidentally drops it. If it winds up in the lake, those eggs hatch and now there are fish. Similar but related, eggs designed to latch onto the feathers of waterfoul like ducks, the feathers fall off when the duck is roosting and bam, now there are eggs in the pond

3: People bringing them there intentionally. Requires probably the least explanation

Anonymous 0 Comments

I found the lake you mention in Google Earth. A few things come into mind. You specifically mention limestone. The location and landscape suggest you’re dealing with something called karst topography, created by limestone dissolving. In these settings, bodies of fresh water can be connected by caves. Changes in topography mean that a lake that is isolated today may have been connected to other bodies of water in the past. Even if the surrounding terrain is too high for flooding to cross it, fish and their eggs sometimes get transported by birds.

Anonymous 0 Comments

Ducks can eat fish eggs, presumably accidentally while eating water plants, and some of the eggs can survive the digestive tract and be pooped out as viable eggs.

Anonymous 0 Comments

Some fish eggs can survive being eaten by birds, and if the bird poops the eggs out while flying over water they can hatch there. Also occasionally strong storms can suck small debris or animals up from oceans, rivers or lakes and rain them down below. If the limestone contains an underwater cave system fish may have accessed the lake from there. It’s possible for one body of water to be split into many isolated bodies of water over the course of hundreds of thousands of years as geographical changes are caused by erosion. There are many possible ways for fish to spread around.

Anonymous 0 Comments

Birds. They eat fish and don’t digest the eggs. Or they’ll drop a live fish in. But usually it is birds

Anonymous 0 Comments

Bird hungry. Bird find fish. Bird fly to far away to eat fish. Bird eat fish and spill guts and eggs in water. Now far away has baby fish.

Anonymous 0 Comments

There are many quarries near me in the middle nowhere and they all have panfish. Only way in is Ducks and Geese

Anonymous 0 Comments

The same as humans spread to North America: now it seems to far to cross with ancient technologies, but it was connected to Asia.
And ones a species is there it can reproduce itself