On the page for Syngnathinae, there are some images of seahorses. I don’t see anything wrong with the observations themselves, so is this a quirk with iNat, a genuine classification thing, or simply an error? After looking up some of the pictured seahorses, I don’t see anything putting them under Syngnathinae.
I’m also curious as to why the subfamily is labelled “Tail-brooding Pipefishes” rather than just pipefishes or pipefishes & seadragons. I’m new to iNat and taxonomy in general, so is this just a taxonomy thing I’ve misunderstood? I can’t seem to find much about pipefishes online other than the generic aquarium pages.
I’ve put this in General as I intended it as an iNat question (the Syngnathinae page, which initially looked off because “seahorse labelled pipefish”), but after doing more research, it may be a bigger taxonomic question for Nature Talk. I’ve kept it here because of the initial iNat question.
It’s a genuine classification thing. A former classification of Syngnathidae (which hasn’t been updated yet on e.g. Wikipedia) divided it into the subfamilies Hippocampinae (seahorses) and Syngnathinae (everything else—all pipefishes, seadragons, etc.). However, it turns out the deepest split in the family isn’t between seahorses and everything else, but is actually between pipefishes with the brood pouch on the male’s trunk and pipefishes etc. with the brood pouch on the male’s tail, and seahorses are deeply nested within the latter clade. Accordingly, the subfamilies were recently revised, moving the trunk-brooders to Nerophinae and lumping seahorses in with the other tail-brooders in Syngnathinae.
(here’s the article that proposed the current subfamily classification, and here’s another more recent one that’s open access)