Hydrophis platurus
Silhouette: Dr Christina Zdenek · PhyloPic
In 3 days ~20% in a week ~50%
The yellow-bellied sea snake (Hydrophis platurus) is an extremely venomous species of snake from the subfamily Hydrophiinae (the sea snakes) found in tropical oceanic waters around the world except for the Atlantic Ocean. For many years, it was placed in the monotypic genus Pelamis, but recent molecular evidence indicates it lies within the genus Hydrophis.
In 1766, Linnaeus published the original description of the yellow-bellied sea snake, naming it Anguis platura (Anguis meaning snake). In 1803, François Marie Daudin created the new genus Pelamis and assigned this species to it, referring to it as Pelamis platuros. In 1842, Gray described what he thought was a new species and called it Pelamis ornata (subsequently P. ornata became a synonym of P. platura). The commonly used genus name Pelamis is derived from the Ancient Greek word for "tunny fish", which presumably refers to the habitat or what Daudin thought they ate. The specific name platurus is a combination of the Ancient Greek words platys "flat" and oura "tail", referring to the flattened tail. The word Pelamis is a feminine noun and means young or small tunny fish. In 1872, Stoliczka introduced the name Pelamis... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Las Baulas Marine National Park | 🇨🇷 Costa Rica | |
| 2 | Piedras Blancas National Park | 🇨🇷 Costa Rica | |
| 3 | Corcovado National Park | 🇨🇷 Costa Rica |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Sydney | 🇦🇺 Australia |
| # | Zoo / Centre | Country | |
|---|---|---|---|
| 1 | Two Oceans Aquarium | 🇿🇦 South Africa |
With luck
About 10% of wildlife watchers report a Yellow-bellied Sea Snake sighting in Piedras Blancas National Park on a given day, based on 13 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 35th most-seen of the 35 reptiles we can rate there. Over three days the chance rises to about 20%, and over a week to about 50%, if each day is a fresh chance.
January and August
In those months about 20% of wildlife watchers report a Yellow-bellied Sea Snake in Piedras Blancas National Park on a given day, against under 5% in April–July and October–November, the lowest months.
Between 9 am and noon
Across all the parks we cover, that three-hour window holds the most Yellow-bellied Sea Snake sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
2nd of 3
Of the 3 parks where we can rate Yellow-bellied Sea Snake sightings, Piedras Blancas National Park ranks 2nd at about 10%. The best odds are in Las Baulas Marine National Park (Costa Rica, about 20%).
GBIF citizen-science records
It is estimated from how often the Yellow-bellied Sea Snake is recorded against all the reptiles logged in Piedras Blancas National Park (13 verified sightings from 2019 to 2026), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
