Chrysaora pseudoocellata, Mutlu & Çağatay & Olguner & Yilmaz, 2020
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publication ID |
https://doi.org/ 10.11646/zootaxa.4790.2.2 |
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publication LSID |
lsid:zoobank.org:pub:15D5BFD4-483C-4EB4-9D69-D12DCFFF8146 |
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persistent identifier |
https://treatment.plazi.org/id/8D521B76-CDD5-42A4-B0CE-F6337BA04076 |
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taxon LSID |
lsid:zoobank.org:act:8D521B76-CDD5-42A4-B0CE-F6337BA04076 |
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treatment provided by |
Plazi |
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scientific name |
Chrysaora pseudoocellata |
| status |
sp. nov. |
Chrysaora pseudoocellata View in CoL sp. nov.
Figures 1–3 View FIGURE 1 View FIGURE 2 View FIGURE 3 , Tables 2 –4
Scyphozoa Goette, 1887
Discomedusae Haeckel, 1880
Chrysaora Péron & Lesueur, 1810
Chrysaora pseudoocellata sp. nov.
Material examined. Holotype: Accession number: ASFM-SCP/2018-0001 , Belek , Eastern Mediterranean Sea , Gulf of Antalya, Turkey, 14 December 2018, 36° 50’ 34’ N, 31° 03’ 62’’ E. Collected by hand by Erkan Biçer from water with a depth of 1 m; 11 cm in umbrella diameter.
Other material examined. Paratypes: Accession number: ASFM-SCP/2018-0002 , Belek , Eastern Mediterranean Sea, Gulf of Antalya, Turkey, 14 December 2018, 36° 50’ 34’ N, 31° 03’ 62’’ E. Collected by hand by Erkan Biçer from water with a depth of 1 m ; 2.8 cm in diameter. ASFM-SCP/2018-0003 , Belek , Eastern Mediterranean Sea, Gulf of Antalya, Turkey, 14 December 2018, 36° 50’ 34’ N, 31° 03’ 62’’ E. Collected by hand by Erkan Biçer from water with a depth of 1 m ; 5.5 cm in diameter. ASFM-SCP/2018-0004 , Belek , Eastern Mediterranean Sea, Gulf of Antalya, Turkey, 14 December 2018, 36° 50’ 34’ N, 31° 03’ 62’’ E. Collected by hand by Erkan Biçer from water with a depth of 1 m ; 10.5 cm in diameter. ASFM-SCP/2018-0005 , Belek , the Eastern Mediterranean Sea, Antalya Gulf, Turkey, 14 December 2018, 36° 50’ 34’ N, 31° 03’ 62’’ E. Collected by hand by Erkan Biçer from water with a depth of 1 m ; 11.5 cm in diameter.
All specimens were deposited with their individual accession number in the Museum of the Fisheries Faculty, Akdeniz University, Antalya, Turkey.
Diagnosis. Chrysaora with strongly granulated, pale exumbrella marked with 16 narrow pigmented stripes radiating from crown, and eight brown rhopalium pits, appearing as conspicuous spots. Umbrella margin with 4–6 marginal lappets per octant, of variable size and shape, without canals; mature specimens with 56 tentacles (7 tentacles per octant), 1 primary tentacles central, 3 secondary tentacles, and 3 tertiary tentacles most peripheral (3-1-3); quadralinga absent.
Description. Holotype 11 cm bell diameter. Umbrella hemispherical ( Figure 1 View FIGURE 1 A–B and 2A), exumbrella surface strongly granulated throughout ( Figure 2 View FIGURE 2 I–J); pale in colour, semi-opaque, with faint and narrow, brown-coloured compass markings dorsally; crown free of pigmentation. With eight small, but conspicuous, pigmented deep brown rhopalial pits ( Figure 2 View FIGURE 2 A–B, Q). Rhopalium bearing a lozenge-shaped (spherical/oval) statocyst ( Figure 2C View FIGURE 2 ) and an elipsoid ocelli ( Figure 2D View FIGURE 2 ) and flanked by a pair of rhopalial lappets, broad and roughly triangular in shape with the deep coloured pit on margin of umbrella ( Figure 2B, M, Q View FIGURE 2 ). Seven marginal tentacles per octant ( Figure 2 View FIGURE 2 G–H), arranged 3-1-3; dorso-ventrally flatted, pale in colour ( Figures 1A View FIGURE 1 _B, 2A, I), longer than bell diameter ( Figure 1A View FIGURE 1 ). Simple radial septa located between stomach and a part between tentacle and sense organ, terminated by the base of the tentacles ( Figure 2 View FIGURE 2 J–K). Stomach without gastric septa ( Figure 2L View FIGURE 2 ). A total of six marginal lappets per octant, not overlapping, and neither uniform in shape or size, those closest to primary tentacle broader than long, those between secondary and tertiary tentacles longer than broad, tongue-like; lappets granulated on exumbrella surface but without canals of gastrovascular system ( Figure 2 View FIGURE 2 G–K). With four oral arms, pale in colour ( Figure 1A, C View FIGURE 1 ), lancet-shaped, two times longer than the bell diameter ( Figure 1A View FIGURE 1 ); not folded basally. Gastric pouch 19.23 mm in length and 5.87 mm in width with the numerous filaments, ( Figure 2L View FIGURE 2 ). Two septa per octant, cylinder-shaped inner margins of the radial septa, with long calyx and long peduncle in equal length, dividing into three parts of the gastrovascular cavity ( Figure 2K View FIGURE 2 ). Gonads attached to rod-like projections rimming gastric filaments through subumbrellar ostia, gonads creamy yellowish, broadly coined in spiral shape, edge (two ends) and middle part not folded and other parts folded in W-shape ( Figure 2L View FIGURE 2 ). Mouth-disc circular, with four evident corners, grooved. Pillars weakly evident, restricted by corners of manubrium. Quadralinga absent. Tentacle cnidome includes heterotrichous microbasic rhopaloid (6.2 - 8.9 µm in length, 3.3–5.8 µm in width and a length/width ratio of 1.2–2.0) ( Figure 2E View FIGURE 2 Table 2), holotrichous A-isorhizas, 1 (6.1–9.8 µm in length, 4.1–6.1 µm in width and length/width 1.3–2.0) ( Table 2) and holotrichous O-isorhizas (4.4–10.8 µm in length, 4.9–10.6 µm in width and a length/width ratio of 1.1 ±0.4 on average ± SD) ( Figure 2F View FIGURE 2 ) ( Table 2). Proportion of holotrichous O-isorhizas: holotrichous A-isorhizas: heterotrichous microbasic rhopaloid was 1.03:1.06: 1 in length and 1.64:1.05: 1 in width. The oral arms had the same types of the cnidomes with similar measurements ( Table 2). However, only one cell of the holotrichous a-isorhizas could be observed on the oral arm.
Variation. Paratype. Specimen ASFM-SCP/2018-0002 (2.8 cm diameter) with eight pale brown radiating ex-
umbrellar stripes ( Figure 2N View FIGURE 2 ); with few marginal tentacles (1-2 mm long) with the least numbers of the tentacles per octant ( Figure 2P View FIGURE 2 ); oral arms partly developed ( Table 3, Figure 2N View FIGURE 2 ); with two poorly developed marginal lappets per octant, rounded, broader than long ( Figure 2N View FIGURE 2 ); not well developed rhopalium and statocyst as an open cylindrical cone (tube-shaped) toward a pit in cone shape ( Figure 2M, P View FIGURE 2 ); gastric pouch lacking filaments ( Figure 2N View FIGURE 2 ).
Paratype. Specimen ASFM-SCP/2018-0003 (5.5 cm diameter) with 40 marginal tentacles, five per octant, arranged as 2-1-2 ( Table 3, Figure 2K View FIGURE 2 ). With four marginal lappets, those flanking primary tentacle broader than long, those between secondary tentacles longer than broad; rhopalial lappets roughly triangular with a deep conic-shaped pit like a crater in brown color on marginal umbrella ( Figure 2B, M View FIGURE 2 ). Gastric cavity 10.49 mm in length and 3.49 mm in width with filaments ( Figure 2N View FIGURE 2 ). Mouth-disc circular, with four evident corners, grooved. Pillars weakly evident, defined by corners of insertion of manubrium in 5 mm wide.
Other specimens as holotype.
Distribution. Eastern Mediterranean Sea, off the coast of Turkey and Israel ( Edelist et al. 2019).
Etymology. The species name refers to the presence of eight brown-coloured rhopalium pits looking like false eye-spots on the umbrella. The English name of the species is the false eyespot sea nettle.
Molecular analysis. Sequences for comparison were obtained from GenBank ( Table 1), supplemented with information from Neethling (2009) and Ras (2017). The COI dataset (655 bp) included 28 taxa, the 16S dataset (598 bp) included 26 taxa and the 28S set (1021 bp) included 25 taxa (24 from NCBI).
As can be seen by reference to Table 3, the genetic distance was measured to be a minimum of 0.10 between Chrysaora pseudoocellata sp. nov. in the present study and a Chrysaora sp. found in the Gulf of Guinea (KY611265.1) and 0.11 between our species and Chrysaora africana (MF141597.1). There was a maximum distance value of 0.33 between Chrysaora pseudoocellata sp. nov. in our study and Chrysaora melanaster (FJ602545.1). COI analysis of all Chrysaora species showed a minimum genetic distance of 0.10 from C. africana and a maximum genetic distance of 0.24 from C. chinensis . The minimum genetic distance for Chrysaora pseudoocellata sp. nov. was 0.102 in a COI matrix with C. africana , 0.053 in a 28S matrix with Chrysaora chinensis and 0.058 in a 16S matrix with Chrysaora pacifica . The maximum values of genetic distance for Chrysaora pseudoocellata sp. nov. were 0.239 in a COI matrix with C. chinensis , 0.129 in a 28S matrix with C. pacifica and 0.202 in a 16S matrix with Chrysaora helvola ( Table 3). A study of the genetic distance using COI gene data for the Chrysaora species showed an estimated genetic distance of 0.162 ± 0.05 and barcode cap varying between 0.02 and 0.06 among the species ( Daglio & Dawson 2017). Of the distances estimated, a minimum genetic distance of 0.10 was estimated between C. pseudoocellata sp. nov. and C. africana , exceeding the threshold value of the barcode gap.
Our molecular analysis results and the high bootstrap values (95-100) in phylogenetic trees ( Figure 3 View FIGURE 3 , S 1 View FIGURE 1 ), confirm that C. pseudoocellata sp.nov. is separated from C. africana and other species. As we know that assessing the biogeographic status of species on the basis of a set of classification criteria such as biogeographic barriers, indirect and direct human agency, and cryptogenic (Essl et al. 2018), our genetic data however does not show that C. pseudoocellata sp.nov. is an invasion from human activities or vessels.
Remarks. The present species cannot be confused with any other in the genus, characterized as it is by its pale colour, prominent dark brown-coloured rhopalial pits and 56 tentacles ( Table 3). Previous records of the species indicate its persistence in the Eastern Mediterranean at least from July 2015 to July 2019, suggesting indeed that populations may be established there ( Edelist et al. 2019). The Mediterranean basin thus appears to be the home of two, possibly three, species of Chrysaora if the Chrysaora cf. achlyos observed by Langeneck et al. (2019) also proves to be resident.
In attempting to explain the (possible) presence of C. cf. achlyos off the coast of Greece, Langeneck et al. (2019) argued that since no species of Chrysaora are found in the Red Sea (citing Morandini & Marques (2010)), it must have been introduced by vessels and/or aquaculture. Although C. pseudoocellata sp. nov. is clearly now a Mediterranean species, we cannot with any real certainty know it is not also found in the Red Sea. It does seem remarkable that a large species such as C. pseudoocellata sp. nov. can remain undetected for so long (see also Drymonema dalmatinum (Haeckel 1880) ( Malej et al. 2014)) but if it can remain hidden in a well-known part of the world, then it would be even more likely to remain hidden in a less well-documented region, such as parts of the Red Sea and the NW Indian Ocean. That said, we should be cautious in considering it an alien species at present (Essl et al. 2018), given the high level of uncertainty and should perhaps consider it data-deficient in this regard.
The present contribution not only unambiguously adds to our understanding of diversity in the Eastern Mediterranean Sea but also highlights the importance of citizen science. Documenting the world’s biodiversity is best done together, and citizen science has a very important role to play in this regard ( Chandler et al. 2017).
TABLE 4. Traits of Chrysaora pseudoocellata sp. nov. DD: Disc diameter (cm), ML: marginal lappets, NMO: number
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