Bycatch: In a good way

By Susan Anthony

As I have written before, I study sea slugs. More specifically, Hermissenda crassicornis. I adore these animals, and I do everything I can to make their stay with me in the sea tables at BMSC comfortable (also with the help of the animal care staff at BMSC). I know they love to eat Obelia sp.(a colonial hydroid cnidarian) and mussels off the dock, so when the weather is nice, I head down to the docks, and delicately remove mussels of the right size, and healthy-looking Obelia for them. When the weather is not so nice, I yank handfuls of Obelia sp. and grab big handfuls of mussels and bring them back to the lab. While there, I sort through the food species, and keep only what I need to feed my darling nudibranchs. Under these conditions, I get a lot of by-catch,that will later in the day be returned to their home off the docks. Some are harder than other to return, just because they are so neat. That is why I write about them here. For a few hours, I have a menagerie of different species, like my very own zoo. Here are a few photos, with my best attempt at identifying them. I hope you enjoy them as much as I did!

Figure 1: Lined chiton (Tonicella lineata). Small in size (this one is about 2cm long), this mollusc has 8 plates along its back, and has a tenacious hold upon a substrate like a rock, or my tanks.

Lined chiton (Tonicella lineata). Small in size (this one is about 2cm long), this mollusc has 8 plates along its back, and has a tenacious hold upon a substrate like a rock, or my tanks.

Figure 2: Juvenile Pisaster ochraceus. As juveniles, these animals are small (about  1cm here), but they can grow to be about 35cm across, and are common along the  intertidal on the Pacific coast. They come in orange, purple, brown, grey, black, and  everything in between. I see the adult versions along the dock, but they are much  easier to avoid collecting.

Juvenile Pisaster ochraceus. As juveniles, these animals are small (about 1 cm here), but they can grow to be about 35 cm across, and are common along the intertidal on the Pacific coast. They come in orange, purple, brown, grey, black, and everything in between. I see the adult versions along the dock, but they are much easier to avoid collecting.

A couple of cute gastropods. On the left, Chlorostoma funebralis (previously known as Tegula funebralis) and also known as the black turban snail. This one has a couple of tag-alongs: an acorn barnacle (Balanus glandula) and white, frilly nudibranch eggs (on the right of the shell). On the right is a blue topsnail (Calliostoma ligatum).

A couple of cute gastropods. On the left, Chlorostoma funebralis (previously known as Tegula funebralis) and also known as the black turban snail. This one has a couple of tag-alongs: an acorn barnacle (Balanus glandula) and white, frilly nudibranch eggs (on the right of the shell). On the right is a blue topsnail (Calliostoma ligatum).

"The

The skeleton shrimp (Caprella sp.), a small, see-through amphipods that use hooks to attach to Obelia sp., and wave their bodies back and forth to capture food from the water. You may not believe it, but they will even hook into your skin if you happen to be handling them (as I do); and they can be quite annoying to get off your hands.

These little nudibranchs (probably Dendronotus frondosus) are even more difficult to see on the Obelia than the skeleton shrimp. They are so well camouflaged  that I have a hard time finding them, until they “run away” from the hydroids, and promenade around the sea tanks.

These little nudibranchs (probably Dendronotus frondosus) are even more difficult to see on the Obelia than the skeleton shrimp. They are so well camouflaged that I have a hard time finding them, until they “run away” and promenade around the sea tanks.

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