1. Biodiversity of dogfishes (genus SQUALUS) in the eastern Atlantic and Mediterranean Sea – a molecular perspective
A. VERÍSSIMO, D. ZAERA-PEREZ, R. LESLIE, S. IGLÉSIAS, B. SÉRET, P. GRIGORIOU, C. GUBILI, J. NAVARRO, C. DUFFY, A.M. GRIFFITHS
European Elasmobranch Association Meeting
9-11 October 2015, Peniche, Portugal

2. The Genus Squalus - Dogfishes
27 species currently accepted
Mostly coastal demersal sharks
Worldwide distribution
<1,5 m total length
Yolk-sac viviparous
Active swimmers

3. SQUALUS – ALPHA TAXONOMY
Many inconsistencies/difficulties in species identification
Poor/ambiguous species descriptions
High morphological similarity among species
Species diversity still not fully described
Twelve new species described from the Indo- Pacific (Last et al. 2007; White & Iglesias 2011)
Many new species previously undetected, other nominal species recently resurrected (Last et al. 2007; Ebert et al. 2010)

4. SQUALUS – ATLANTIC OCEAN sensu lato
Five species currently recognized
S. acanthias (VU)
S. blainville (DD)
S. cubensis (DD)
S. megalops (DD)
S. mitsukurii (DD)
Taxonomic issues
Difficulties in species identification
S. mitsukurii may be a species complex

5. OBJECTIVES
Re-evaluate species-level diversity of Squalus in the eastern Atlantic & Mediterranean
Molecular markers (mtDNA COI, 551 bp)
Morphology (meristics & morphometrics)
Biology (life history traits)

6. SAMPLING
Specimens sampled de novo along the eastern Atlantic & Mediterranean
DNA sequences (N=128)
Whole specimens as vouchers
Additional COI sequences from GenBank and BOLD.org (N=288)
- Worldwide distribution
- Multiple Squalus species
19 Squaus species represented (out of 27)

7. “megalops-cubensis” - group
SQUALUS - COI data
“acanthias” - group
100%
100%
“megalops-cubensis” - group
97%
“blainville” - group

8. CLADE 1: “acanthias” group
Atlantic, Mediterranean, S. Pacific
100%
N. Pacific
N. Pacific
© Monterey Bay Aquarium

9. CLADE 2: “megalops – cubensis” group
96%
Gulf of Mexico
Australia
89%
100%
Kermadec Islands, New Zealand
Mediterranean, Portugal – South Africa
Portugal
86%
Japan & Taiwan
Mediterranean,
Portugal – South Africa
© Museu História Natural e Ciência

10. Zooming into the megalops-like subgroup
Atlantic and Mediterranean megalops-like may be considered a separate species,
with widespread distribution in the Mediterranean and eastern Atlantic.
White starts show locations with “megalops”-like specimens sampled in this study. Map shows currently accepted distribution of S. megalops.

11. CLADE 3: “blainville” group
100%
Australia
Uruguay & South Africa
Indonesia & Australia
97%
95%
Australia
Gulf of Mexico
Uruguay, Gulf of Mexico, Guine-Conakri/Bissau
99%
Tunisia & Gabon
Indonesia & Australia
Indonesia
94%
Australia
89%
Taiwan
86%
90%
Australia
New Zealand
87%
Indonesia & Australia
89%
87%
Hawaii
Taiwan

12. Squalus blainville CLADE 3: Squalus blainville type
100%
97%
95%
99%
Is this the “true” S. blainville??
Type locality is Nice, France.
Most specimens identified as S. blainville clustered into the “megalops” group.
Tunisia & Gabon
94%
According to Muñoz-Chaplli & Ramos (1989), Risso’s description of A. [S.] blainville agrees well with several species in the genus… For nomenclatural stability, the long-snouted Squalus of the Mediterranean was kept as S. blainville.
89%
86%
90%
87%
89%
87%

13. The megalops vs. blainville issue
Biological Data
Risso 1826 is the original description of S. blainville. According to Muñoz-Chapulli & Ramos, Risso’s description can fit in with several species in the genus… For the sake of nomenclatural stability, have proposed to keep the taxon name to designate long-snouted Squalus from the Mediterranean and eastern Atlantic. ??

14. The megalops vs. blainville issue
Several diagnostic characters have been proposed by previous studies, but this has not clarified the ambiguity in species identification and the issue of inconsistency species identification has been perpetuated.

15. What about S. mitsukurii?
100%
Australia
Uruguay & South Africa
97%
95%
Gulf of Mexico
Uruguay, Gulf of Mexico, Guine-Conakri/Bissau
99%
94%
89%
86%
90%
87%
89%
87%
Hawaii

16. Zooming into the mitsukurii-like specimens
Atlantic “mitsukurii” are genetically distinct from Hawaiian specimens, and likely form distinct species.
Unresolved status among Atlantic “mitsukurii”.
Type locality of S. mitsukurii Jordan & Snyder 1903 is Japan. The Hawaiian “mitsukurii” may or may no be the “true” mitsukurii, but the Atlantic “mitsukurii” appear as very distinct lineage(s).

17. Presence of cryptic diversity in the Eastern Atlantic!
Summary
Inconsistent use of the taxon names S. blainville and S. megalops in the Mediterranean and Eastern Atlantic.
Atlantic & Mediterranean megalops-like specimens may be a distinct species from the Australian megalops.
Very distinct Atlantic vs. Pacific lineages currently designated under the taxon name S. mitsukurii.
Presence of cryptic diversity in the Eastern Atlantic!

18. Acknowledgements
To those that have contributed with samples and/or data
Funding agencies