Some name suggestions for the kids! I tried so hard to think but it's late and I'm tired lmao.
Walrusheart; I tried so hard to think of an "oceanclan" type suffix. I know heart is basic, but his quickness to defend his siblings made me think Walrusheart would fit! Another suffix would be Walrusdive, due to his interest in fun facts; Taking a deep dive, as one would say
Flipperswim; Flipperkit's said to enjoy things that work her mind and physical activity- Swimming is something that is often used as physical activity, particularly in shallow water to work muscles especially amongst pets! (I imagine as adults they're.. Less afraid of the water now? I hope at least, so Sharkstar doesn't seem like an asshole naming her that LOL)
Tuskreef; While reefs are often used for fish to hide from predators, reefs are also a good place to lay eggs and stay with mates. Tusk's tendency to stay with their family no matter how shy they feel is what motivated Shark to give them this name!
ofc, just suggestions, but those are what I thought of. Tuskreef is my fav lmao
OOH I LIKE THOSE THOSE ARE REALLY GOOD
and I like the thought you put into their names and how you considered their personalities! I think 'heart' fits Walrus a lot (dive does too but he's really sweet so I like him having the heart suffix), Flipperswim is so fun to say, and Tuskreef sounds so good!!!