Berghia creutzbergi Er. Marcus & Ev. Marcus, 1970
- Millereolidia ritmica (Ortea, Caballer & Espinosa, 2003)
- Milleria ritmica Ortea, Caballer & Espinosa, 2003
- Spurilla creutzbergi (Er. Marcus & Ev. Marcus, 1970)
Description
Body up to 30mm long, coloured grey, cream or brown, with large yellowish-white oval spots on the head, behind the rhinophores and the dorsal interceratal areas, also on the cerata. These spots are formed by a dense aggregate of white dots. The cardiac area is also white, prominent and with a slightly wrinkled surface. The rhinophores have a grainy surface like a raspberry, and arise from a single smooth basal peduncle. Their external sides are somewhat concave and the internal ones almost flat; they present 11 rings with 6-8 regular sized granules (6 at the tips) of which the two apical rings and the mucron are yellowish white, as are the two central posterior granules of each ring, originating a white vertical band along each rhinophore; the rest of the granules are of the same hue as the body. The oral tentacles are long and cylindrical, truncated at the tip, with the base as the body colour and golden tips. The cerata contract when the animal is in motion so they look globose, also with the base as the body colour and golden upper half and apex. When the animal is at rest, the cerata lower half become slimmer and stretched, doubling the extension they have in motion. There are five regularly separated groups of cerata on each side of the body. The biggest cerata are located on the anterior-uppermost part of the flank and they increase in number and decrease in size to the lower part of the flank. The number of cerata in each group was: 15 (1st): 7 (2nd): 7 (3rd): 5 (4th) and 3 (5th). The genital opening is below the first group of cerata, very close to their base and the anus in the first right group of postcardiac cerata. The anterior border of the foot is rounded and has wide base angles with the tentacular prolongation facing rearward; the sole is wider than the body and of the same colour. The tail is formed by a sharp thinning of the animal’s body behind the last cerata.
Biology
Lives in shallow water with seagrass bed and high hydrodinamism. Cerata rock from side to side when the animal is in motion, a very distinctive rhythmic movement. The animal is able to stand on the thin tail with the rest of the body free to sense its surroundings, then choose a direction and move that way. It also appears that the brown background colour of the body is caused by zooxanthellae in ducts of the digestive gland, ramifying through the body wall.
Etymology
- Berghia. In honor to the Danish doctor and malacologist Dr. Rudolph Bergh, (1824-1909).
- Creutzbergi. Possibly named after Dr. Peter Hans Creutzberg, a Dutch biologist and filmmaker of nature who lived in Colombia, where he collected molluscan fossils.
Distribution
Reported in the tropical Western Atlantic, in Florida, Costa Rica, Venezuela, Cuba, Barbados, Bahamas, Cayman Islands, Curaçao, Brasil (Valdés et al., 2006; Carmona et al., 2014) and Panamà (Goodheart et al., 2016). There is a report in the Eastern Atlantic, in Tufia, Gran Canaria, Spain (Sabina López, Pers.Com.).
| Sources: | |
 : OBIS : GROC 2010-2011 : Enric Madrenas : João Pedro Silva : Bernard Picton : GBIF.ORG |  : OPK : VIMAR : Manuel Ballesteros. : M@re Nostrum : Altres fonts : Marine Regions |
Abundance
| Western Mediterranean: | ☆☆☆☆☆ |
| Eastern Mediterranean: | ☆☆☆☆☆ |
| Atlantic Ocean: | ★☆☆☆☆ |
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Further reading
Cite this article as:
Pontes, Miquel, Manuel Ballesteros, Enric Madrenas (2023) "Berghia creutzbergi" in OPK-Opistobranquis. Published: 07/02/2021. Accessed: 04/06/2023. Available at (https://opistobranquis.info/en/1pK0N)
