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)!
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…