Berthella stellata (Risso, 1826)

This widely ranging and many-named notaspidean is characterized by a semi- translucent body color and a dorsal streak of white running perpendicularly across its notum. But as with all biological organisms, there is variation. Sometimes the white bar is not present, or occurs as a broken hashed line. Sometimes the body is a bit more less translucent. As Gosliner and Bertsch (1988) stated, "The body is generally translucent white to honey brown." The specimens illustrated are at the honey brown range of coloration; some completely lack the transverse opaque white band. Berthella stellata was originally named from animals collected in the Mediterranean. Since then, and often under various synonyms, it has been reported from the Red Sea, southern Africa, Australia, Hawaii, the Caribbean, and the eastern Pacific (including the Pacific coast of the Baja California peninsula and inside the Gulf of California). Additional images of the animal, shell, radula, and reproductive system can be seen in Bertsch (1975) and Gosliner & Bertsch (1988). Orso Angulo, José Luis Arreola (hatless) and I have recently conducted several intertidal research expeditions at Bahía Tortugas, Baja California Sur. Our research is supported by a grant from the Mexican federal government conservation agency, CONABIO (Comisión Nacional para el Conocimiento y Uso de la Biodiversidad). Orso and José Luis are (respectively) student and faculty at the Universidad Autónoma de Baja California Sur, in La Paz. We have made two expeditions to Bahía Tortugas. During these expeditions, we have seen and recorded 95 specimens of Berthella stellata. In December 1997 we found 59 specimens (average length 14.8 mm) and 31 egg masses; in February 1998 we counted 36 specimens (average length 15.7 mm) and 5 egg masses. We hope that our ongoing expeditions will give us a better understanding of the life history of this interesting creature, and the other opisthobranch species in the region of Punta Eugenia and the nearby islands of Cedros and Natividad. The photograph of Berthella stellata and egg masses is an in situ portrait, taken by José Luis Arreola, in the intertidal region near the former Institute of PESCA laboratories, Bahía Tortugas. This is the first published illustration of the egg mass of this species. Send Orso e- mail at mol@lapaz.cromwell.com.mx Text courtesy of Hans Bertsch and Orso Angulo

LITERATURE CITED

Bertsch, Hans. 1975. Distributional and anatomical observations of Berthella tupala (Opisthobranchia: Notaspidea). Nautilus 89 (4): 124-126.
Gosliner, Terrence M., and Hans Bertsch. 1988. A review of the genus Berthella (Opisthobranchia: Notaspidea) from the Pacific coast of North America. The Veliger 31 (1/2): 46- 67.

Dr. Hans Bertsch 192 Imperial Beach Blvd. #A Imperial Beach, CA 91932 FAX (619) 423-9118 Send Hans E-Mail at hansmarvida@cox.net

---