LOUI, Kienberger & Carmona & Pola & Padula & Gosliner & Cervera, 2016

Kienberger, Karen, Carmona, Leila, Pola, Marta, Padula, Vinicius, Gosliner, Terrence M. & Cervera, Juan Lucas, 2016, Aeolidia papillosa (Linnaeus, 1761) (Mollusca: Heterobranchia: Nudibranchia), single species or a cryptic species complex? A morphological and molecular study, Zoological Journal of the Linnean Society 177 (3), pp. 481-506 : 499-502

A EOLIDIA LOUI SP. NOV.

LSID URN:LSID:ZOOBANK.ORG:ACT: D79111E0- 0229-4C75-82DA-33C86AF49E5F

( FIGS 7D , 9G, H , 12A – E )

Aeolidia herculea , not A. herculea Bergh, 1894 ; Smith & Gordon, 1948: 181.

Aeolidia papillosa , not A. papillosa (L., 1761); Er. Marcus, 1961b: 54, plate 10, figs 193 – 195.

Aeolidia papillosa herculea , not A. herculea Bergh, 1894 ; MacFarland, 1966: 370, plate 72, figs 1 – 8.

Aeolidia sp. B : Carmona et al. (2013: 6).

Material examined. Holotype: CASIZ 182214 , one specimen, dissected, 30 mm in length preserved, USA, California, Marin Country, Duxbury Reef, i.10, collected by Terrence M. Gosliner. Paratype: CASIZ 102425 , one specimen, dissected, 28 mm in length preserved, USA, California, vii.76, collected by T. Pennington and D. Thoney . Other material: CASIZ 104504 , one specimen, dissected, 20 mm in length preserved, USA, California, v.05, collected by Rebecca Johnson and Christine Piotrowski ; CASIZ 168044 , one specimen, dissected, 20 mm in length preserved, USA, California, iv.03, collected by R. Ayres, C. Brown, M. Walton, and S. Lattanzio .

Type locality and habitat. USA, California, Marin Country , Duxbury Reef. Found in intertidal area, within tide pools and under the rocks .

Geographical distribution. To date, this species is distributed from Cape Arago, Oregon, to San Diego, California, USA .

Etymology. This species is dedicated to Lou Timothee Menelik von Graffenried Kienberger, first nephew of the first author of this paper.

External morphology ( Fig. 12A–E ). The body is broad and relatively low, narrowing to the posterior end of the foot. The foot corners are tentaculiform. The coloration is variable, ranging from translucent white ( Fig. 12A – C ) to bright orange or brown ( Fig. 12D ). Over the dorsum there are opaque white marks that may be covered by light-ochre and brown flecks, and/or spots. The white marks may form a somewhat uniform patch that runs, like the Y – shaped mark, from the head to the posterior end of the foot. The rhinophores and oral tentacles present the same colour as the body and light tips. The rhinophores are conical, blunt, and covered by irregular warts ( Fig. 12E ). The eyes are visible at the base of the rhinophores. The oral tentacles are elongate and translucent, with opaque white pigments.

The cerata are somewhat bristly, flattened, and broader at their base, with pointed tips. Those at the anterior region and near the posterior end of the foot are smaller than those in the middle. There is a bare zone from behind the rhinophores to the pericardium. The cerata are translucent and have the same coloration as the background colour of the body. White pigment or spots cover both edges of the cerata. This pigmentation may reach the proximal two-thirds of the cerata. The ochre, greenish, or brownish digestive gland is visible throughout the body wall. The cerata are arranged in up to 24 rows, and are extremely densely packed. Each row has between four and 30 cerata, decreasing in size towards the posterior end of the foot. Behind the pericardium the cerata rows join across the back, forming an arch that goes from one side of the body to the other. The cleioproctic anus is situated between the ninth and tenth rows on the right side, whereas the genital aperture is located between the right fourth and fifth rows.

Internal anatomy ( Fig. 7D , 9G–H ). The jaws have a smooth masticatory edge ( Fig. 9G ). The radular formula is 16 X 0.1.0 ( CASIZ 182214, 30 mm). The teeth are progressively smaller towards the posterior region of the radula and present 41 – 45 denticles ( Fig. 9H ). Salivary glands were not found. Oral glands are absent.

The reproductive system is diaulic ( Fig. 7D ). The preampullary duct widens into the narrow, elongate, and moderately short ampulla. The ampulla bifur- cates into the oviduct and the vas deferens. The vas deferens is quite long and convoluted, entering the wider proximal portion of the penial sac. The penial papilla is devoid of any armature. The somewhat rounded receptaculum seminis joins the oviduct and enters the female gland. The vagina opens ventrally to the penis.

Remarks. In the past, specimens of Aeolidia collected from Californian shores were named A. papillosa , A. herculea Bergh, 1894 ; or A. papillosa herculea MacFarland, 1966 ; by several authors ( Smith & Gordon, 1948; Er. Marcus, 1961b; MacFarland, 1966). Ernest Marcus (1961b) attributed the Californian specimens of Aeolidia to A. papillosa , describing them as pink with occasionally red cerata. Additionally, their cerata were flattened, broader at their base, leaving a free space in the anterior region just over the heart. Marcus (1961b) also illustrated the radular teeth of these specimens. Some years later, specimens from Monterey Bay and Waddel Creek Reef were attributed to A. papillosa herculea by MacFarland (1966). He provided detailed information about the coloration of the living animal (dull rose or mauve) and its radular teeth.

As the coloration, the ceratal shape, and the morphology of the radular teeth of A. loui sp. nov. match with the specimens found by Er. Marcus (1961b) and MacFarland (1966), we concluded that all are conspecific and belong to an undescribed species.

Regarding A. herculea , this species is a deep-water aeolid ( Behrens, 2004). Therefore, all of the specimens studied by the above authors, together with those of Smith & Gordon (1948) and McDonald (1983), cannot be attributed to A. herculea because they were collected from shallow waters. Gosliner & Behrens (1996) described A. farallonensis from material collected at 1405 – 1491 m depth. This species is currently considered as the junior synonym of A. herculea ( Martynov & Korshunova, 2011) . We consider that A. herculea and A. loui sp. nov. are not the same species, as our specimens reside in shallow waters. Also, there are significant morphological differences between these two species, especially in the position of the anus: whereas A. herculea is pleuroproctic, A. loui sp. nov. has a cleioproctic anus situated between the ninth and tenth rows on the right side.

The bristly cerata and the warty rhinophores of A. loui sp. nov. easily distinguish it from the remaining Aeolidia species. This is the first time that an Aeolidia species is described with ‘papillate’ rhinophores. Moreover, it should be mentioned that this ornamentation of the rhinophores is lost when the specimens are preserved. This would explain why Er. Marcus (1961b) and MacFarland (1966) depicted A. loui sp. nov. rhinophores as smooth.

Figures

Figure 7. Reproductive system: A, Aeolidia papillosa, the Netherlands (MNCN 15.05/65211); B, Aeolidia campbellii (ZSM 20041026, 20 mm), Chile; C, Aeolidia filomenae sp. nov., France; D, Aeolidia loui sp. nov. (CASIZ 102425), California, USA. Scale bars: 2.0 mm. Abbreviations: am, ampulla; fgm, female gland mass; ps, penial sac; rs, receptaculum seminis; va, vagina; vd, vas deferens.

Figure 9. Scanning electron micrographs. A, B, Aeolidia campbellii (ZSM 20041026, 20 mm); A, detailed view of the masticatory border, scale bar 1000 µm; B, radular teeth, scale bar 500 µm. C, D, Aeolidia filomenae sp. nov. (MNCN 15.05/74470); C, detailed view of the masticatory border, scale bar 300 µm; D, radular teeth, scale bar 200 µm; E, F, Aeolidia filomenae sp. nov. (MNCN 15.05/74475); E, detailed view of the masticatory border, scale bar 500 µm; F, radular teeth, scale bar 400 µm; G, D, Aeolidia loui sp. nov. (CASIZ 182214); G, detailed view of the masticatory bor- der, scale bar 10 µm; H, radular teeth, scale bar 30 µm.

Figure 12. Photographs of live Aeolidia loui sp. nov. specimens: A, holotype, specimen from USA, California, photo by Terrence M. Gosliner (CASIZ 182214); B, specimen from USA, California, photo by Patricia Alvarez-Campos and Greg Rouse; C, specimen from USA, Oregon, photo by Nancy Treneman; C, specimen from USA, California, photo by Gary McDonald; E, detail of the rhinophores of the specimen from USA, California, photo by Dave Behrens.