Silly spider crabs…

I have been doing some field work the past few weeks, one of the reasons for infrequent postings, so I apologize.  This week, I saw some cool things.  Well the things I saw were not so cool – they were spider crabs, and I see them ALL THE TIME.  (In fact, I’d be more surprised to not see any spider crabs.)  But it was what I saw the spider crabs DOING this week that was so cool.

While snorkling at a site in Heady Creek, Shinnecock Bay, NY, I came across this creepy (and dead) bluefish.  It was pretty big, and it was being picked at by a spider crab.  I know that spider crabs are typically considered scavengers, and this particular crab is no different. But its one thing to watch spider crabs picking on a dying whelk. Its something different, or rather, interesting to see them doing on this bluefish. Maybe its just funny, as I typically wish there were more large fish to consume all the spider crabs, as they eat bivalves, including my precious scallops.

And then I saw this amazing site – a spider crab, while clinging to one of my spat bags, was also clinging to a sea nettle, my assumption is to eat it. And after reading about ctenophores found in dogfish stomachs, and a recent article in Science about bearded gobies consuming jellies, it makes me think “Ecological dead-end my ass!” Well, lets not get too ahead of ourselves, but still interesting to see this today (and according to the Smithsonian Marine Station, spider crabs do eat jellies):

Plus they were just crawling all over things, including my recruitment tiles and into the eelgrass canopy (hey I thought only mud crabs did that)!

Spider crab crawling up eelgrass
Spider Crab on my recruitment tile

These little guys do some pretty interesting things.  From typically scavenging, consuming vegetation, carrion and detritus, to possibly actively hunting – including on shellfish and probably jellies, maybe we need to reconsider the role of spider crabs in our coastal ecosystems. Maybe…

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