Aurelia solida, SOLIDA BROWNE, 1905

Scorrano, Simonetta, Aglieri, Giorgio, Boero, Ferdinando, Dawson, Michael N. & Piraino, Stefano, 2017, Unmasking Aurelia species in the Mediterranean Sea: an integrative morphometric and molecular approach, Zoological Journal of the Linnean Society 180 (5), pp. 243-267 : 259-260

AURELIA SOLIDA BROWNE, 1905

Aurelia solida Browne, 1905: 960 – 962 , pl. 94, figs 1 – 2. Type locality: Maldives.

Aurelia TET lineage Schroth et al., 2002: 3, 4 (table 2) (Red Sea, Mediterranean Sea). Aurelia sp. 8 Dawson et al., 2005: 11970, fig. 1 (Adriatic, Mediterranean, Red Sea). Ram̃sak et al., 2012: 70 (North Adriatic, Mediterranean Sea).

Material examined: Holotype: Female, GT, March 2015, 24 cm BD. Deposited in UNIPD. Accession number: CN58 CH.

Paratype I: Female, GT, March 2015, 150 mm BD. Accession number: UNIS _SCY_038 .

Other material: Seven medusae, GT, March 2015, 134 – 220 mm (range of BD); one medusa, PC, April 2013, 218 mm BD. All specimens deposited in UNIS _SCY. Accession numbers: UNIS _SCY_039 – 046.

Description (based on holotype and paratypes): Morphometric and meristic data of polyp and ephyra stages are presented in Table 1. Morphology is illustrated in Figures 5C , 8P – T , 9D , and 11I – L . Molecular diagnosis is presented in Figures 3 and 4 .

Polyp: Number of tentacles variable, commonly 16 – 22, rarely 14. Tentacles ramified in 40% of polyps. Hypostome cruciform. Colour pinkish.

Asexual reproduction by budding from stolon or directly from column of parental polyp. Podocysts also observed. Strobilation polydisc, up to 20 discs observed.

Ephyra: Normally eight arms, 16 marginal lappets, and eight rhopalia. Marginal lappets long, breadknife-like shaped ( Straehler-Pohl & Jarms, 2010; Fig. 8P ). Colour milky – transparent. Manubrium cruciform. One or two gastric filaments per quadrant.

Medusa: Disc rounded, thick, up to 24 cm in diameter. Bell margin salmon – light violet, bell shape (f21) typically undulating, with eight marginal lobes and eight marginal sense organs in a deep cleft (f29, 5.26 ƚ 0.2 mm). The sense organ is protected on the exumbrellar side by a dorsal hood of rhomboidal – oval shape ( Fig. 11I ). The rhopalium is short and directed mostly towards the exumbrellar side, approximately angled at 90 ° with respect to the direction of rhopalia described in A. coerulea and A. relicta sp. nov. ( Fig. 11J ), where rhopalia are directed towards the bell margin. The same pattern was described in the original description given by Browne (1905), in comparison with A. aurita .

A large ectodermal ocellus is visible. The reddish pigment granules are arranged in a top-hat shape, with a middle row projecting towards the upper end ( Fig. 11K ). No endodermal ocellus was detectable on the subumbrellar side ( Fig. 11L ).

Numerous small and pinkish tentacles are arranged slightly above the bell margin. Manubrium cruciform, rigid, depth 4 – 8 mm, width 21 – 27 mm, with four perradial oral arms slightly folded, mean length (f5) 8 r /9.

Four interradial gonads, horseshoe-shaped, rose – violet. Subgenital pore placed centrally, diameter (f11) ranging from 3.5 to 5.6 mm. Opposite gastric cavities close across the diameter, mean proximal gastric diameter (f9) from r /6 to r /3, distal gastric diameter (f10) from 3 r /4 to r. From each gastrogenital sinus, between six and nine canals depart (ranges of variation: two or three perradials, between one and three adradials, and between two and four interradials). Canals salmon – violet. Adradial canals (f28) branched a few times, interradial (f26) and perradial canals (f27) branched up to 36 times.

Type locality: Maldive islands (Arabian Sea, Indian Ocean).

Habitat: Marine, open sea. Only one record from coastal lagoon in the Mediterranean Sea.

Distribution in the Mediterranean Sea: Bizerte Bay and Lagoon ( Tunisia), Gulf of Trieste (North Adriatic sea), Porto Cesareo (Ionian Sea), Cannes ( France).

Distribution outside Mediterranean Sea: Arabian Sea, Red Sea, Maldive Islands, Indian Ocean

( Schroth et al., 2002; Dawson et al., 2005; Ram̃sak et al., 2012).

Remarks: Migration through the Suez Canal and shipping from the Indian Ocean seem to be the most conceivable sources of introduction and spread in Mediterranean open-water areas ( Dawson et al., 2005).

Figures

Figure 3. COI–28S concatenated maximum-likelihood tree reconstructed using GARLI 2.0. Numbers adjacent to nodes show the bootstrap support values. The scale indicates the number of substitutions per site. Reference sequences from GenBank are in bold.

Figure 4. Bayesian species tree estimated using *BEAST (COI + 28S). Numbers adjacent to nodes show the posterior probability values. The scale indicates the estimated number of substitutions per site.

Figure 5. Interspecific morphological differences in the anastomoses and bell indentations: A, Aurelia coerulea (= Aurelia sp. 1), female, bell diameter (BD) = 125 mm; B, Aurelia relicta sp. nov. (= Aurelia sp. 5), immature specimen, BD = 95 mm; C, Aurelia solida (= Aurelia sp. 8), male, BD = 160 mm.

Figure 8. Development of the gastric system in Aurelia ephyrae from four Mediterranean locations, reared in the laboratory: A–E, Aurelia coerulea (= Aurelia sp. 1), EH; F–J, Aurelia coerulea (= Aurelia sp. 1), VL; K–O, Aurelia relicta sp. nov. (= Aurelia sp. 5), ML; P–T, Aurelia solida (= Aurelia sp. 8), GT. Scale bars: 1 mm.

Figure 9. Morphology of Aurelia spp. polyps: A, Aurelia coerulea (= Aurelia sp. 1), EH; B, Aurelia coerulea (= Aurelia sp. 1),VL; C, Aurelia relicta sp. nov. (= Aurelia sp. 5), ML; D, Aurelia solida (= Aurelia sp. 8), GT. Scale bars: 1 mm.

Figure 11. Structure of marginal sense organ in Aurelia medusae: A–D, Aurelia coerulea (= Aurelia sp. 1), bell diameter (BD) = 136 mm; E–H, Aurelia relicta sp. nov. (=Aurelia sp. 5), BD = 95 mm; I– L, Aurelia solida (= Aurelia sp. 8), BD = 144 mm. The rhopalium is directed towards the bell margin in A. coerulea (B) and A. relicta sp. nov. (F), angled at ~90° in A. solida (J). Abbreviations: ec. o, ectodermal ocellus; en. o, endodermal ocellus.