Dale Pollard
The biblical account of Jonah being swallowed by a “great fish” (often called a whale) has long been under scrutiny by biblical skeptics. This short investigation hits a few different areas that may give the reader some more food for thought.
We’ll cook up a theory using—
- Some historical maritime context of ancient seafaring practices
- A sprinkle of marine biology
- A pinch of paleontology
- A tad of textual linguistics
- A ladle of literary evidence
With all that we’ll explore some plausible candidates for the big fish.
Potential Location of the Storm and Jonah’s Route
The Mediterranean stretch between Rhodes and Cyprus was notoriously treacherous. Jonah sailed from Joppa (modern Jaffa, Israel) toward Tarshish (likely Spain), covering approximately 430 oceanic miles from Rhodes to Joppa or a neighboring Phoenician port. The route passed close by Rhodes and Cyprus, exposing vessels to sudden violent storms.
This seems to be a decent area to focus on. While other parts of the Mediterranean are known to be more dangerous, they’re closer to Spain. No marine animal capable of swallowing a human could make that swim in just three days. While it could have been a specialized super-swimmer designed by God— for the purpose of this article we’re going to stick with candidates that were currently aware of.
Candidate Creatures
1. Sperm Whale
Probably the most common theory, for good reason. Sperm whales have
• Large sinus air chamber and integrated blowhole allowed any gobbled prophets to breathe.
• Massive throat capable of swallowing large prey whole instead of crushing or suffocating
2. Fin Whale (Detailed Physiology)
From the Christian Research Journal (Vol. 48, No. 03, 2025), the fin whale’s lunge-feeding allows it to engulf enormous volumes of water (60–82 m³). Its forestomach can hold ~500 L of fluid, but the narrow esophagus (~10 cm) suggests Jonah was likely held in the expandable oropharynx (“belly”). Survival challenges include trauma, hypothermia, slippery surfaces, and air supply (mitigated by frequent surfacing every 5–15 minutes).
3. Basilosaurus (extinct)
• Fits biblical themes of large serpentine sea monster (Amos 9.3)
• Fluid-filled bones for near-surface swimming
• Elbow-like fins for shallow-water maneuverability, ideal for expelling prey onto beaches.
• Ancient artwork in the region resembles it. This is perhaps the coolest point that we’ll revisit.
4. Megalodon (Otodus megalodon)
• Largest known shark in the ancient Mediterranean, up to 50 feet long.
Was It a Whale, a Fish, or a “Ketos”?
Hebrew dag gadol (“great fish”) and Greek ketos (used in the Septuagint and Matthew 12:40) are general terms for a large sea creature or monster, not precise biological categories. Historian Bill Cooper and others note that ketos consistently referred to a dog-headed sea-dragon or serpent in ancient Mediterranean mind. Dr. Henry Morris notes its “mega-sized” connotations.
Ancient writers used specific terms for such creatures, while New Testament authors employed broader language.
Ancient Literary and Artistic Evidence for the “Ketos”
Historical evidence from authors and historians who best knew the Mediterranean Sea consistently used ketos to mean “a sea serpent.”
This is supported by:
• Literary sources (from ca. 700 B.C. onward): Homer (9th–8th century B.C.), Euripides, Aristophanes, Lycophron, Aristophanes (various dates), Manilius, Marcus Terentius Varro, Diodorus Siculus, Claudius Aelianus, Oppian of Apamea, Pausanias, Eustathius, Hesychius, and Johannes Moschus, among others.
Artistic depictions:
First-century paintings from a Roman catacomb show Jonah being thrown into the sea monster with a dog-like head, flexible neck, and often coiled body. Numerous artifacts (carvings, coins, ivory, wood, stone) depict the ketos with a dog-like head, prominent teeth, plume-like flaps or frills above the head and neck, and a slender, coiled form. These consistent renderings across Rome, Africa, Turkey, and elsewhere strongly identify the ketos as a sea serpent.
The visual and textual tradition closely resembles creatures like Basilosaurus and supports a naturalistic but still divinely orchestrated interpretation of the biblical “monster.”
BONUS:
Interesting Historical Sighting
Strabo records Poseidonius’ eyewitness account (ca. 130–51 BC) of a massive “fallen dragon” (~30 m / 100 ft long) on the northern Levant coast with enormous jaws. It was so big that two riders on horse back couldn’t see each other if they were on either side of its belly.
Bonus Notes:
Clues from Jonah’s Prayer (Jonah 2)
• Repeated references to depth and deep water.
• “Moors or roots of the mountains” — possibly the Eratosthenes Seamount near Cyprus.
• Calypso Deep is the deepest point, Jonah might be referring to it.
Travel Feasibility
A blue whale’s comfortable speed of ~5 mph could cover ~360 miles in the relevant Rhodes-area voyage, making that in distance in 72 hours (three days).
References:
• Christian Research Journal, Vol. 48, No. 03 (2025).
• Brian Thomas, Ph.D., Institute for Creation Research.
• Bill Cooper, The Authenticity of the Book of Jonah (2012/2013).
• Dr. Henry Morris on ketos.
• Strabo, Poseidonius, and the extensive list of classical authors cited.
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