Some fin fishy: Brother swapped sister's goldfish for carrots and she didn't notice

It's a truth universally acknowledged that siblings will play tricks on one another. But replacing your sister's goldfish with a carrot? That's definitely a new one.

Twitter user @SamuelAnnis is behind this fiendish prank. He removed her two goldfish from their bowl and put baby carrots in their place. What's worse, he claims, she hasn't noticed now for four days... and counting.

The bizarre and slightly disturbing episode has been documented by Annis and uploaded onto Twitter where, of course, it has gone viral. One of the pictures alone has garnered nearly 200,000 likes and 70,000 retweets.

It is unknown how old the siblings are but, given his mischievousness and her gullibility, one would hope that they haven't yet reached high school. Also, we have to assume that Annis's version of events is actually true and not a wider prank on social media users and journalists.

In a series of tweets Annis claims that after replacing the goldfish with the carrots he told his sister that they were lying inanimate on the floor of their bowl because they were about to give birth.

He said that his sister 'fed' the carrots with sprinklings of fish food and continued to wait for them to give birth for four days.

Annis has assured concerned Twitter users that the real goldfish remain unharmed.