A blue rockfish that was inflicted with a parasitic copepod called Sarcotaces.
A blue rockfish that was inflicted with a parasitic copepod called Sarcotaces. (Contributed photo)

Question: I speared a 15” blue rockfish at Ocean Cove over Labor Day weekend. It had a large belly but no eggs or anything extraordinary within its stomach or fillets. Within the gut cavity, attached to the end of the intestine (near the anus), there was a 3.5 cm white mass with a black tip at the free end.

It was very hard and calcified. I cut it in half longways and found that the translucent white skin came off easily, but the black mass inside was very dense. The black mass also seems to rub off and stain anything it touched, like a gummy charcoal.

I took pictures, with pink arrow on Gyotaku print of this fish marking the approximate location and orientation within gut cavity. Is this some kind of parasite, or just a calcified gonad/kidney stones? Would this mass give any reason to avoid eating the fillets? 


Answer: What a vivid description you provided! And the photos are very helpful for reference.

The condition you’ve described is caused by a parasitic copepod called Sarcotaces. Copepods are arthropods and are in the same taxonomic group of animals as crabs and insects.

The “mystery mass”

The juvenile Sarcotaces can be found in the water column in hopes of finding a host. In this case, the host was the rockfish you caught.

Sarcotaces inserts its head into the skin of a fish and is eventually encapsulated by the fish’s flesh, except for the last body-segment which maintains connection with the outside seawater.

This parasite is commonly found in rockfish, usually located near the vent where the surrounding intestinal tissue forms a sac-like protuberance inside the abdominal cavity. Sarcotacesfeed on blood from the fish, and the digested blood becomes a dark fluid or paste inside the sac. When the parasite dies, the tissue forms a closed cyst, which is what you found during filleting.

There are no human health concerns with a fish infected with Sarcotaces, although if the fillets become tainted with the dark fluid from a ruptured sac they may become visually unappealing to eat. Careful removal of the parasitic sac and handling of the fish as usual is recommended.

Sharing a video with CalTIP?

Question: I took a video of what I think is a wildlife crime in progress. I know you have a tip line, but how can I submit the video?

— Anonymous

Answer: With modern phones being capable of taking high definition video and photographs, the California Department of Fish and Wildlife (CDFW) is seeing an increase in the number of CalTIP reports that include video or photographs.

You can submit a video or photograph to CalTIP in one of four ways. 

First, you can send your tip and video or photograph to CalTIP by SMS text message, by texting “CALTIP”, followed by a space and the message, to 847411 (tip411). You can attach a media file to the SMS text message as you normally would if you were texting with a friend. 

You can also use the CalTIP app, which can be downloaded for free via the Google Play Store and iTunes App Store. The app gives you the option to attach a video or photograph before you submit your report.

If you choose to report through the CalTIP website, select “Report a Violation online.” This will take you to an online reporting form where you will have the option of attaching a file, including a video or photograph.

Lastly, you can attach the file to an email and send it to caltip@wildlife.ca.gov. When sending a photograph or video via email, please submit any details about the violation you witnessed, along with the media file. If you are submitting a photo or video related to an investigation in progress, please include the CalTIP reference number. 

Any time you make a report with CalTIP, please be prepared to provide as many incident details as you can – time of occurrence, location, vehicles involved (including license plate numbers, when possible), physical description of the suspects, the species targeted and what you believe the violation to be. The more details you provide to our wildlife officers, the faster they can put a stop to any illegal activity.

Carcass removal?

Question: Who can I call about a dead bear on my property?

— Beverly

Answer: With some exceptions, removal and disposal of wildlife carcasses is not a service that CDFW provides. If you believe the bear may have been poached, please report it to CalTIP, 1-888.334.2258, and a wildlife officer will contact you.

If the bear has an ear tag, please contact the closest regional office to speak with a biologist.

Otherwise, your local or city authorities may offer options, such as pickup and transport to a rendering plant.

Carrie Wilson is a marine biologist with the California Department of Fish & Wildlife. She can be reached at cwilson@dfg.ca.gov.