Baeolidia Bergh, 1888

Miller, M. C., 2001, Aeolid nudibranchs (Gastropoda: Opisthobranchia) of the family Aeolidiidae from New Zealand waters, Journal of Natural History 35 (5), pp. 629-662 : 653-654

Genus Baeolidia Bergh, 1888 .

Baeolidia Bergh, 1888: 777 ±778; Bergh, 1892: 1019; Eliot, 1903: 252 ±254; O’ Donoghue, 1929: 795; Allan, 1947: 460; Baba, 1955: 32 ±33, 54.

Diagnosis

Body fairly wide and low, oral tentacles moderately long, wide at base, tapered, rhinophores approximately same length, club large, evenly and densely ringed with papillae, stalk short, outer lips of mouth papillate: cerata broadly oval, ¯attened, cover back completely, arranged in arches with forwardly bent limbs, rear limb shortening progressively towards tail: cleioproctic, anus within second arch, renal pore abanal, reproductive apertures at tip of hind limb of ®rst arch: front of foot curved shallowly, upper lip notched in middle, angles fairly long and tapered: oral glands small, club shaped: radular tooth a wide arch, blade narrowish, largest denticles in middle gradually becoming smaller toward tips of limbs, no cusp; jaw masticatory process smooth: bursa copulatrix duct long.

Type species. (By monotypy) Baeolidia moebii Bergh, 1888 .

Bergh based his genus Baeolidia on a single preserved specimen, which he described as new, collected on the island of Mauritius. This species, B. moebii , the type of the genus, has been found only once since then ( O’Donoghue, 1929). The second specimen, taken from the Suez Canal, is said to be identical with the ®rst except for the mid line gap in the radular teeth with a minute cusp, part ringed and part papillate rhinophoral club, digitiform ¯attened cerata, and in cross section closer to Eolidina (Berghia) coerulescens than Aeolidia . These features suggest that they are not the same. This means that we can rely only on the description of the type specimen for the generic diagnosis. Notwithstanding this, other species have been assigned to the genus the ®rst being B. major Eliot. This has caused controversy as some believe that certain of these species do not belong to Baeolidia . The problem for me here is including Baeolidia australis , together with the closely related species named below, in this genus. As indicated by others these species do not ®t the genus because of diOEerences in two charactersÐpositions of the reproductive apertures and anus. In B. moebii the reproductive apertures lie below the third row of cerata and the anus between ceratal rows 6 and 7. It is possible to reconcile the positions of the reproductive apertures by suggesting that in a contracted preserved specimen they might be seen to lie close to the tip of the third ceratal row. However, the position of the anus is di cult to settle, the position in B. moebii being further back than the second arch. If Bergh did not remove the cerata, then it is possible that he misidenti®ed the position of the anus. Another possibility is that the anus was in a variant position. My experience is that the ceratal arrangement and anal position can be plotted accurately only after the removal of the cerata. All of the other characters are Baeolidia -like Ðform of the rhinophoral club, oral tentacles and cerata and their disposition (rows merged bowlike), anterior end of foot, radula and jaws ®t exactly. It is this which persuades me that B. australis and the other named species can be admitted to this genus. More than anything, Bergh’s remark`like Aeolidia ’ has convinced me of this. Other than the species named above, only the large Aeolidiella species look like Aeolidia .

Gosliner (1985) has placed Aeolidiopsis harrietae Rudman, 1982 in the genus Baeolidia together with his very similar B. palythoae . These two species with their inclined rows of cerata and bilobed radular teeth do not ®t my understanding of the genus based on ceratal arrangement and tooth shape. I consider them diOEerent from though close to Aeolidiopsis and suggest that they should be placed in a new genus.