DIVE DRY WITH DR. BILL #816: SLIGHTLY OFF TARGET
Back in the days when I used to hunt pigs ("wild boar") for ecological control and to help provide food for our school kitchen, I was a pretty good shot both with my rifle and my handguns. However, when I tried bow hunting, my arrows were usually well off target. Cupid would be appalled. But I'm not here to discuss culling the feral pigs that were impacting our native plants and animals. Today the "target" of my writing will be the peanut rock or target rock shrimp or prawn (Sicyonia penicillata).
I have never seen a target shrimp in Catalina waters despite diving to depths of 200 fsw. The only place I have observed them is down in Sandy Eggo. Fortunately I have dive friends who dive and image there more frequently than I do and I'm relying on two of them, Kevin Lee and Weiwei Gao, for the images and description of mating in this column.
Way down south in Mexican waters there is an important fishery for these shrimp, known there as camarón blanco. Back in the early 1970s several of us took a large group of our students from the Catalina Island School down to Bahia de Kino on the mainland coast of the Sea of Cortez near the Midriff Islands. One of our adventures down there was to board a shrimper to collect specimens for The L.A. County Museum of Natural History.
Most of the fish and invertebrates we collected were bycatch from the shrimp nets. It was my first real introduction to how destructive the shrimp fishery can be to benthic (bottom) communities. I must admit that I didn't complain when the boat crew cooked all the shrimp and halibut we could eat for $1 each! My feeble memory can't image the species of shrimp the boat "targeted," so I don't remember if they were "targets" or some other prawn species. After all, several species live in the Gulf of California (Sea of Cortez) and I was a young and less experienced marine biologist back then. A study of prawn abundance off Bahia de Kino suggests we may have been taking brown shrimp rather than target or rock shrimp. However as other species of prawns have declined in abundance, target shrimp have increased in importance.
This species ranges from Costa Rica up into southern California. Many sources fail to include the northernmost distribution, assuming the species is limited to south of the border, but others include San Diego, Los Angeles and even Monterey. It may be found at depths from about 85 to nearly 900 feet on sandy or mud bottoms. Our region (the Sea of Cortez and SoCal) actually has as many as 12 species of target shrimp
Thanks to a video of mating target shrimp by Weiwei, I can relate to you the courtship behavior of this species. As usual, the males seem hopped up on hormones (like so many species) and follow the females from behind in a ritualized form of foreplay that can last quite a while. I'm sure half of our own species would greatly appreciate this. It is triggered both by chemical pheromones and touch.
From what is seen in the video, the female eventually raises her abdomen and the male moves beneath it and flips onto his back. That must be one of the positions in the Shrimp Kama Sutra, but I don't have a copy in my library. Sperm is transferred to the female in a matter of seconds and they go off on their merry way. Often the courtship behavior seems to be synchronized with many pairs forming at the same time. That reminds me of the "Love Ins" during the late 1960s that I (sadly) didn't really participate in.
© 2019 Dr. Bill Bushing. For the entire archived set of over 800 "Dive Dry" columns, visit my website Star Thrower Educational Multimedia (S.T.E.M.) Home Page
Image caption: Target rock shrimp midwater and head region (thanks to Kevin Lee) and screen grabs from Weiwei Gao's video of them mating.
Back in the days when I used to hunt pigs ("wild boar") for ecological control and to help provide food for our school kitchen, I was a pretty good shot both with my rifle and my handguns. However, when I tried bow hunting, my arrows were usually well off target. Cupid would be appalled. But I'm not here to discuss culling the feral pigs that were impacting our native plants and animals. Today the "target" of my writing will be the peanut rock or target rock shrimp or prawn (Sicyonia penicillata).
I have never seen a target shrimp in Catalina waters despite diving to depths of 200 fsw. The only place I have observed them is down in Sandy Eggo. Fortunately I have dive friends who dive and image there more frequently than I do and I'm relying on two of them, Kevin Lee and Weiwei Gao, for the images and description of mating in this column.
Way down south in Mexican waters there is an important fishery for these shrimp, known there as camarón blanco. Back in the early 1970s several of us took a large group of our students from the Catalina Island School down to Bahia de Kino on the mainland coast of the Sea of Cortez near the Midriff Islands. One of our adventures down there was to board a shrimper to collect specimens for The L.A. County Museum of Natural History.
Most of the fish and invertebrates we collected were bycatch from the shrimp nets. It was my first real introduction to how destructive the shrimp fishery can be to benthic (bottom) communities. I must admit that I didn't complain when the boat crew cooked all the shrimp and halibut we could eat for $1 each! My feeble memory can't image the species of shrimp the boat "targeted," so I don't remember if they were "targets" or some other prawn species. After all, several species live in the Gulf of California (Sea of Cortez) and I was a young and less experienced marine biologist back then. A study of prawn abundance off Bahia de Kino suggests we may have been taking brown shrimp rather than target or rock shrimp. However as other species of prawns have declined in abundance, target shrimp have increased in importance.
This species ranges from Costa Rica up into southern California. Many sources fail to include the northernmost distribution, assuming the species is limited to south of the border, but others include San Diego, Los Angeles and even Monterey. It may be found at depths from about 85 to nearly 900 feet on sandy or mud bottoms. Our region (the Sea of Cortez and SoCal) actually has as many as 12 species of target shrimp
Thanks to a video of mating target shrimp by Weiwei, I can relate to you the courtship behavior of this species. As usual, the males seem hopped up on hormones (like so many species) and follow the females from behind in a ritualized form of foreplay that can last quite a while. I'm sure half of our own species would greatly appreciate this. It is triggered both by chemical pheromones and touch.
From what is seen in the video, the female eventually raises her abdomen and the male moves beneath it and flips onto his back. That must be one of the positions in the Shrimp Kama Sutra, but I don't have a copy in my library. Sperm is transferred to the female in a matter of seconds and they go off on their merry way. Often the courtship behavior seems to be synchronized with many pairs forming at the same time. That reminds me of the "Love Ins" during the late 1960s that I (sadly) didn't really participate in.
© 2019 Dr. Bill Bushing. For the entire archived set of over 800 "Dive Dry" columns, visit my website Star Thrower Educational Multimedia (S.T.E.M.) Home Page
Image caption: Target rock shrimp midwater and head region (thanks to Kevin Lee) and screen grabs from Weiwei Gao's video of them mating.
