Salmon?
You'd expect the males to be bigger if they're territorial, so anything with a redd or a nest might have bigger males. Anyone know? Sticklebacks, lumpsuckers, pipefish, cichlids, seahorses?
Coelacanth, where art thou?
Otherwise, most fish play the numbers game, casting their eggs out to whatever fate awaits them and bearing the loss - that means LOTS of eggs, which means MUCH bigger females.
Another tactic, used by quite a few sharks, is live-bearing; this means big young, but fewer of them, so big females may help here...
The ultimate in sexual dimorphism is (or was, when I was a student) one of the deep-sea angler-fish. In such a food-poor environment, it is a disadvantage to waste a feeding opportunity on a mere male, when it could be put to better use making eggs - so the males have to find a female early in their lives (HOW, fergawdssake? I must have dozed off in that part of the lecture...) and hang onto her so tightly he becomes a parasite - and a dwarf, a mere sperm-factory drawing just enough from his mates blood-stream to keep body and spermatogenesis together.
Certain women would draw parallels, so careful who reads this...
---------- Post added at 23:25 ---------- Previous post was at 23:18 ----------
Salmon? You'd expect the males to be bigger if they're teritorial, so anything with a redd or a nest might have bigger males. Anyone know? Sticklebacks, lumpsuckers, pipefish, cichlids, seahorses? Coelacanth, where art thou?
Otherwise, most fish play the numbers game, casting their eggs out to whatever fate awaits them and bearing the loss - that means LOTS of eggs, which means MUCH bigger females.
Another tactic, used by quite a few sharks, is live-bearing; this means big young, but fewer of them, so big females may help here...
The ultimate insexual dimorphism is (or was, when I was a student) one of the deep-sea angler-fish. In such a food-poor environment, it is a disadvantage to waste a feeding opportunity on a mere male, when it could be put to better use making eggs - so the males have to find a female early in their lives (HOW, fergawdssake? I must havedozed off in that part of the lecture...) and hang onto her so tightly he becomes a parasite - and a dwarf, a mere sperm-factory drawing just enough from his mate's blood-stream to keep body and spermatogenesis together.
Certain women would draw parallels, so careful who reads this...
---------- Post added at 23:27 ---------- Previous post was at 23:25 ----------
Oops! Only wanted to put an apostrophe in "mate's" and it double-posted. Sorry!