Slender sunfish

Slender sunfish
Temporal range: Early Miocene to present
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Division: Teleostei
Order: Tetraodontiformes
Family: Molidae
Genus: Ranzania
Nardo, 1840
Species:
R. laevis
Binomial name
Ranzania laevis
(Pennant, 1776)

The slender sunfish (Ranzania laevis) is a mola of the family Molidae, the only extant member of the genus Ranzania, found globally in tropical and temperate seas. Its length is up to 1 m (3.3 ft). Several stranding and mass stranding events have occurred on beaches near Albany, Western Australia.

The first South Australian specimen was found at Aldinga in 1944. A cast was made from it, and a replica was made, painted and prepared for display at the South Australian museum that year. Several other individuals have stranded in South Australia at Port Willunga, Netley and West Beach with the latter successfully returned live to deeper water.

In contrast to its much larger relatives in the family Molidae, who are very slow-moving and feed almost exclusively upon jellyfish, salps, and small fish and crustaceans, analysis of stomach contents show that the slender sunfish also consumes squid, particularly of the family Ommastrephidae, which are known for being very fast-moving, displaying evidence that the slender sunfish itself is a faster-moving and agile predator of squid. Unlike its relatives, which possess dull, rough skin, the slender sunfish displays brilliant, silvery hexagonal scales across its body which are smooth to the touch.

Several other fossil species of Ranzania are known:

In addition, a partial fossil of an indeterminate Ranzania is known from the latest Miocene (Messinian) of Algeria. An indeterminate Early Miocene-aged molid, known from a single fossil beak from the Gaiman Formation of Chubut, Argentina, may also be that of Ranzania; this fossil is notable for representing the southernmost record of fossil Tetraodontiformes. During the warmer climate of the Miocene, the now-frigid coast of Chubut may have been more hospitable for pelagic molids like Ranzania.

References

  1. ↑ Liu, J.; Zapfe, G.; Shao, K.-T.; Leis, J.L.; Matsuura, K.; Hardy, G.; Liu, M.; Tyler, J.; Robertson, R. (2016) [errata version of 2015 assessment]. "Ranzania laevis". IUCN Red List of Threatened Species. 2015 e.T193615A97668925. Retrieved 1 July 2024.
  2. ↑ Matsuura, K. (2014): Taxonomy and systematics of tetraodontiform fishes: a review focusing primarily on progress in the period from 1980 to 2014. Ichthyological Research, 62 (1): 72–113.
  3. ↑ "A Marine Rarity. Shoal of Stranded Sunfish". The West Australian. 1928.
  4. ↑ "Albany Sunfish. Rare Fish Found Locally". Albany Advertiser. 1941.
  5. ↑ "Rare Sunfish Found At Aldinga Beach". Advertiser (Adelaide, SA : 1931 - 1954). 1944-06-20. p. 6. Retrieved 2019-06-25.
  6. ↑ "Sunfish Which Is Rare And Distinctly Unfishy". Advertiser (Adelaide, SA : 1931 - 1954). 1944-09-13. p. 4. Retrieved 2019-06-25.
  7. ↑ "Sunfish sightings in South Australia". Marine Life Society of South Australia Inc. 2014-08-09. Retrieved 2019-06-25.
  8. ↑ "Slender Mola (Ranzania laevis)". iNaturalist.org. 15 May 2019. Retrieved 2019-06-25.
  9. ↑ Nyegaard, M.; Loneragan, N.; Santos, M. B. (2017). "Squid predation by slender sunfish Ranzania laevis (Molidae)". Journal of Fish Biology. 90 (6): 2480–2487. Bibcode:2017JFBio..90.2480N. doi:10.1111/jfb.13315. ISSN 1095-8649. PMID 28470845.
  10. ↑ "Large Pelagics Research Lab- bluefin tuna, leatherback turtles, climate change, Mola mola". www.tunalab.unh.edu. Archived from the original on 2011-08-19. Retrieved 2026-09-13.
  11. ↑ Bray, D.J. (2024). "Ranzania laevis in Fishes of Australia". Fishes of Australia. Retrieved 14 Sep 2026.{{cite web}}: CS1 maint: url-status (link)
  12. ↑ "PBDB Taxon". paleobiodb.org. Retrieved 2025-02-26.
  13. 1 2 Kazuo Sakamoto, Teruya Uyeno (1994). "Ranzania ogaii, a new Miocene slender mola from Saitama, Japan (Pisces: Tetraodontiformes)". Bulletin of the National Science Museum. Series C. Geology & Paleontology. 20 (3). January, 1999: 109–117. Retrieved 7 October 2024 – via J-Global.
  14. ↑ "PBDB Strata Results". paleobiodb.org. Retrieved 2025-02-26.
  15. ↑ Carnevale, Giorgio (2007). "Fossil fishes from the Serravallian (Middle Miocene) of Torricella Peligna, Italy". Palaeontographia Italica (91): 1–67.
  16. ↑ "Record of the slender mola, genus Ranzania (Teleostei, Tetraodontiformes), in the Miocene of the Chelif Basin, Algeria". Comptes Rendus Palevol (in French). 6 (5): 321–326. 2007. doi:10.1016/j.crpv.2007.04.001.
  17. ↑ "Tetraodontiformes (Osteichthyes, Actinopterygii) from the Miocene of Argentina: with the southernmost record of fossil Tetraodontidae". Comptes Rendus Palevol (in French). 20 (27): 585–596. 2021. doi:10.5852/cr-palevol2021v20a27.

Abu El-Regal and El-Moselhy. 2013. The first record of slender sunfish, Ranzania laevis from the Red Sea. Journal of Fish Biology. 83(5):1425-9 DOI: 10.1111/jfb.12226