Cal. Fish & Game Code § 8598
(a) Notwithstanding Section 8140 or subdivision (b) of Section 8597, specimens of the following groups or species shall not be taken, possessed aboard a boat, or landed for commercial purposes. Taking, possessing, or landing of any of the following species in a commercial operation is prima facie evidence that it was taken, possessed, or landed for commercial purposes:
(1) Invertebrates:
(P) Opisthobranchia (including nudibranchs)—all subclass Opisthobranchia species except:
(2) Vertebrates:
(3) Live rocks.
(b) No organisms may be taken, possessed, or landed for marine aquaria pet trade purposes under the terms of a marine aquaria collector’s permit in any of the following areas: