Aplysia elongata, (PEASE, 1860)

Golestani, Haleh, Crocetta, Fabio, Padula, Vinicius, Camacho-García, Yolanda, Langeneck, Joachim, Poursanidis, Dimitris, Pola, Marta, Yokeş, M. Baki, Cervera, Juan Lucas, Jung, Dae-Wui, Gosliner, Terrence M., Araya, Juan Francisco, Hooker, Yuri, Schrödl, Michael & Valdés, Ángel, 2019, The little Aplysia coming of age: from one species to a complex of species complexes in Aplysia parvula (Mollusca: Gastropoda: Heterobranchia), Zoological Journal of the Linnean Society 187, pp. 279-330 : 306-307

APLYSIA ELONGATA ( PEASE, 1860)

( FIGS 4E–H, 14E–G, 15A, 16D–F, 17A)

Syphonota elongata Pease, 1860: 24 . Type locality: ‘ Sandwich Islands’ (= Hawaiian Islands). Syntypes: Dry shell 15.8-mm long (MCZM 298486); dry shell 9.2-mm long (MCZM 031442).

Additional material examined: Napili Bay , Maui , Hawaiian Islands , 13 June 2011, one specimen 3.5 mm preserved length, leg. D. Hanson, J. Alexander, J. Goodheart, A. Valdés ( CPIC 00300 , isolate HG5); 15 June 2011, one specimen 5 mm preserved length, leg. D. Hanson, J. Alexander, J. Goodheart, A. Valdés ( CPIC 00325 , isolate HG18). Maliko Bay , Maui, Hawaiian Islands, 18 June 2011, one specimen 3.5 mm preserved length, leg. D. Hanson, J. Alexander, J. Goodheart, A. Valdés ( CPIC 00363 , isolate HG6); one specimen 1.5 mm preserved length, leg. D. Hanson, J. Alexander, J. Goodheart, A. Valdés ( CPIC 00368 , isolate HG21). Maui, Hawaiian Islands, 16 June 2011, one specimen 8 mm preserved length, leg. D. Hanson, J. Alexander, J. Goodheart, A. Valdés ( CPIC 00333 , isolate HG9) .

Description: Morphological characteristics as in description of species complex 3. Radular formula 22 × 3.6.1.6. 3 in an 8-mm long preserved specimen from Maui, Hawaiian Islands ( CPIC 00333, isolate HG9).

Range: Appears to be endemic to the Hawaiian Islands.

Remarks

In this study, we found only one species of Aplysia parvula s.l. present in the Hawaiian Islands, including six sequenced specimens. This species appears to be endemic to this archipelago and no other species has been found there. A search of the literature reveals that only one name was introduced for A. parvula s.l. based on material collected from the Hawaiian Islands.

Pease (1860) described Aplysia elongata based on an undetermined number of specimens collected in the Hawaiian Islands. The specimens were described as brown, darker on top of the head and neck, with an oblong body, an elevated dorsum and strongly dilated and undulated parapodia, free nearly the entire length. No illustrations were provided. We have access to photographs of several syntypes of A. elongata ( Fig. 4E–H) (dry shells), which are consistent morphologically with those of other specimens of A. parvula s.l. Engel (1936) regarded A. elongata as a valid subspecies of A. parvula , restricted to the Pacific Islands and Australia. Engel (1936) included in this subspecies the original description by Pease (1860) from the Hawaiian Islands and records from Samoa by Eliot (1899) as A. nigrocincta , from the Society Islands by Pease (1868) as Siphonota punctata and from Norfolk Island and Sydney, Australia by Sowerby II (1869) and Allan (1932) as A. norfolkensis . Eales (1960) considered A. elongata as a probable synonym of A. parvula .