A/N: A Gobi fish and Shrimp have the cutest symbiotic relationship ever. The shrimp is almost blind, and the Gobi has perfect eyesight but can't really build itself a home. The shrimps are very good at digging caves and generally have an antennae on the side of the fish to figure out where it's going. The fish look out for enemies and go back into the cave whenever they see one. The shrimp knows the fish is gone and it's not safe, and finds it's way back into the cave. If it can't, the fish will generally come back in and lead it to safety.
John Gobi woke up slowly. His cave-mate was prodding him into awareness, and wasn't being gentle, using his big claw to prod into John's soft skin. Sherlock Shrimp was urging him to get going, so he could build their cave more. John didn't understand why Sherlock always had to be doing something, and unlike other shrimp, Sherlock never went back to caves he'd already dug, so they were always moving. Mrs. Hudson Shrimp was always behind them, cleaning up after Sherlock was finished to make sure the caves were actually habitable. Her Gobi wasn't around all the time, and spent most of his time in an old cave near the one Sherlock was currently digging, which was right beside the current food patch.
"Sherlock, I'm hungry." John said, swimming towards the mouth of their shared cave, looking forward to catching food.
"Don't use that entrance," Sherlock said, and his antennae left John's side as the shrimp crawled away.
"Why not?" He asked, swimming back to Sherlock. He wouldn't tell anyone, but he always got a little anxious when he couldn't feel the light, comforting touch of Sherlock's antennae on his side.
"Because we used it yesterday, and it's boring." The shrimp explained, "Here, I'll make you another one."
And the Sherlock went on to dig another entrance, but not before he closed up the other one. John was used to his shrimp getting bored of entrances and making new ones, But he always felt a little claustrophobic when there wasn't a way out of their cave, and it was pitch dark. It didn't matter to Sherlock, who was almost blind, but to John and his perfect eyesight, it was frightening.
Most couples looked at these two with shaking heads, no one knew how John could stand Sherlock, because he was so different from most shrimp. He was almost blind, yes, but he had too much confidence compared to most shrimp. John was Sherlock's eyes, but that was where their relationship stopped being normal. Sherlock was always moving, never content with the location of their cave. He was also terrifyingly smart.
John's thoughts were cut off by a burst of light into their cave. A new entrance. He stuck his head out the mouth of the cave, looking out for danger while Sherlock finished the entrance, his antennae always resting lightly on John's side. John caught little bits floating by for his breakfast. He then paused to think about the last time his companion had eaten... Three days ago.
"Sherlock, get some food for yourself." He told his shrimp.
Sherlock seemed a little wary but slowly left the cave with minimal argument. John moved with him, leading him slowly towards the shrimp's current food patch, which was almost gone. He filed the thought of looking for another one for later. Sherlock grabbed some of the food, but he went almost too close to the anemone that stood near them. Moriarty Anemone was a dangerous anemone and liked to tease Sherlock. Both of them had bad eyesight, and it was really scary to John, who always tried to swim out of the way of the shock. It was hard for him to leave Sherlock even though he knew he was very likely to get out of any fight.
"Sherlock! Get out!" he hissed at his shrimp.
"John? Where are you?" Sherlock asked, trying to figure out which dull shape was his Gobi.
John darted quickly near the anemone and put his fin near Sherlock's antennae. He used that to guide sherlock out and back near their cave, only getting a couple shocks. It was still enough to scare him.
Once inside, he noticed another Gobi in their cave.
"Hi Anthea." He said, a little upset that Sherlock's brother had come to visit.
Sure enough, from behind Anthea, a shrimp came out.
"Hello brother dear." He said.
"Mycroft." Was sherlock's reply.
"I want you to get rid of that anemone, it's becoming a pain for everyone. Even though not many people know about it. It's doing other things than guarding the food sources..."
John Gobi sighed, it was just another day for him and Sherlock Shrimp.