Elysia flava Verrill, 1901

Krug, Patrick J., Vendetti, Jann E. & Valdés, Ángel, 2016, Molecular and morphological systematics of Elysia Risso, 1818 (Heterobranchia: Sacoglossa) from the Caribbean region, Zootaxa 4148 (1), pp. 1-137 : 47-48

publication ID

https://doi.org/ 10.11646/zootaxa.4148.1.1

publication LSID

lsid:zoobank.org:pub:91353147-FDA8-45CC-A8F1-1DE801C835A6

DOI

https://doi.org/10.5281/zenodo.5664183

persistent identifier

https://treatment.plazi.org/id/A04A7E6D-9C61-FFB3-46C9-FF78FE761F69

treatment provided by

Plazi

scientific name

Elysia flava Verrill, 1901
status

 

Elysia flava Verrill, 1901 View in CoL

( Figs. 6 View FIGURE 6 I, 21–23)

Elysia flava Verrill 1901: 30 View in CoL , pl. 4, fig. 1 (Type Locality: Castle Harbor at Waterloo, Bermuda) — Pruvot-Fol 1946: 35; Er. Marcus 1957: 414; Thompson 1977: 124 –125, figs. 25a, 26e; Ev. Marcus 1980: 66; Clark 1984: 90 –91, figs. 22–24; Espinosa & Ortea 2001: 44; García et al. 2002: 50, fig. 2G; García et al. 2008: 71; Collin et al. 2005: 690; Espinosa et al. 2005: 56; Valdés et al. 2006: 68 –69; Krug et al. 2015: 990 –991, figs. 3B, 4.

Type material. Elysia flava —untraceable, not at YPMNH.

Material examined. Isla Chimana Grande, Venezuela, July 1989, 3 specimens ( LACM 178625 About LACM , LACM 178625 About LACM [2 in lot]); Cayo Solarte , Bocas del Toro , Panama, 21 February 2004, 1 specimen ( LACM 2004-9.1 ) ; Piscadera Bay, Curaçao, July 2010, 1 specimen ( LACM 173252 About LACM ) .

Live animal. Animals are typically found under rocks during the day and not associated with any specific alga.

External anatomy. Color yellowish-orange, with some conical opaque white papillae on sides and edges of parapodia ( Fig. 21 View FIGURE 21 ). Edges of parapodia with line of opaque white pigment. Some scattered white spots also present on head and rhinophores. In most specimens digestive gland visible through skin as blotches of dark grey or black pigment. Body relatively short, wide and tall. Rhinophores relatively large, rolled, thick, with rounded blunt tips. Parapodia tall, thick, undulated edges when animal is resting and straight when animal is moving. Eyes conspicuously visible.

Renopericardium indistinct from pericardium on preserved specimens. One long pair of posterior dorsal vessels running length of body ( Fig. 22 View FIGURE 22 ). Numerous lateral vessels emerging from each main vessel; side vessels running up side of parapodium, most unbranched but a few forking once or twice.

Internal anatomy. Radula with 18 teeth (LACM 178626), 6 teeth in the ascending limb and 11–12 in the descending limb ( Fig. 23 View FIGURE 23 A). Leading tooth elongate, with a slightly curving cusp tip, bearing a short denticulate keel and at least one smooth lateral edge ( Fig. 23 View FIGURE 23 B). Housing depression for interlocking teeth extending ½ total tooth length ( Fig. 23 View FIGURE 23 A). Base of the tooth approximately ½ total tooth length. Ascus containing jumbled heap of discarded teeth (not figured).

Penis robust and cone-shaped, devoid of armature. Deferent duct long, thin, and convoluted ( Fig. 6 View FIGURE 6 I).

Reproduction and development. No data available.

Host ecology. Little is known about this enigmatic species, with no published data on larval development mode or host alga. In the eastern Atlantic Marín & Ross (1988) found intact chloroplasts in the digestive system possibly of Cladophora sp., suggesting this alga could constitute the diet of E. flava . The sister species E. obtusa (see below) feeds on Bryopsis , which is another potential host alga for E. flava .

Phylogenetic relationships. The sister species of E. flava is the morphologically similar Elysia obtusa Baba, 1938 from the Pacific; these two species form a clade sister to a diverse clade including many Bryopsis -feeding taxa ( Fig. 4 View FIGURE 4 ).

Range. Belize ( Clark & DeFreese 1987), Bermuda ( Verrill 1901; Clark 1984), Brazil ( García et al. 2002, 2008), Costa Rica ( Espinosa & Ortea 2001; Valdés et al. 2006), Cuba (Espinosa et al. 2005), Curaçao (present study), Jamaica ( Thompson 1977), Panama ( Collin et al. 2005), Puerto Rico ( Ev. Marcus 1980), Venezuela ( Valdés et al. 2006), and Mediterranean Sea ( Thompson & Jaklin 1988).

Remarks. Elysia flava is easily recognizable alive by its translucent yellowish color with the dark green branching of the parapodial digestive gland visible though the skin, and the presence of opaque white rounded papillae along the edge of the parapodia.

This species was first described by Verrill (1901) from Bermuda, in the western Atlantic, followed by several records from the Caribbean (see range section). The first eastern Atlantic record was by Thompson & Jaklin (1988) from the eastern Mediterranean. The Pacific species Elysia obtusa Baba, 1938 is very similar externally and has been considered a synonym ( Gosliner et al. 2008). However, Trowbridge et al. (2011) questioned this synonymy based on the geographic range separation between E. obtusa and E. flava . Our molecular phylogenetic analyses confirm that Indo-Pacific specimens of E. obtusa are genetically distinct from E. flava ( Fig. 4 View FIGURE 4 ), and indeed represent a valid species.

LACM

Natural History Museum of Los Angeles County

Kingdom

Animalia

Phylum

Mollusca

Class

Gastropoda

Order

Sacoglossa

Family

Plakobranchidae

Genus

Elysia

Loc

Elysia flava Verrill, 1901

Krug, Patrick J., Vendetti, Jann E. & Valdés, Ángel 2016
2016
Loc

Elysia flava

Krug 2015: 990
Garcia 2008: 71
Valdes 2006: 68
Collin 2005: 690
Garcia 2002: 50
Espinosa 2001: 44
Clark 1984: 90
Ev 1980: 66
Thompson 1977: 124
Pruvot-Fol 1946: 35
Verrill 1901: 30
1901
GBIF Dataset (for parent article) Darwin Core Archive (for parent article) View in SIBiLS Plain XML RDF