Alatina alata: The Lunar Box Jellyfish

Species profile · Last reviewed 3 November 2026

Alatina alata is a tropical, open-water box jellyfish that becomes unusually visible when adults gather near shore to reproduce. At well-studied sites, spawning aggregations have been recorded about 8–10 days after the full moon. That is a pattern documented in particular places—not a universal beach forecast or proof that moonlight alone causes the migration.^[1]

Its story also includes a scientific name change: specimens once called Alatina moseri in Hawai‘i and A. mordens in Australia were brought together with Caribbean A. alata through comparative anatomy and DNA. Below, we separate what researchers have observed from what remains uncertain.

Alatina alata at a glance

What does Alatina alata look like?

Researchers describe a tall, narrow, transparent bell that tapers toward a truncated top, with four wing-like pedalia at the corners and a tentacle emerging from each pedalium. Fine features—including the arrangement of the eyes, the canals in the velarium, and microscopic stinging capsules—help distinguish it from other box jellies. A quick beachside glance is not a dependable species identification: many details are hard to see in a living, nearly transparent animal, and older specimens can lose or obscure diagnostic features.^[2]

For a guided tour of the structures that scientists compare, see our labeled box jellyfish anatomy guide. Identification is a research task, not a reason to approach or handle an animal.

Why has its scientific name changed?

The name Carybdea alata dates to an 1830 description that gave little information about where the specimen came from. No original type specimen was available to settle later disagreements. In 2005, the genus Alatina was established, and taxonomists moved the old species name into it as Alatina alata. A 2013 redescription from Bonaire designated a neotype—a new name-bearing specimen—to stabilize the identity of the 1830 name.^[2]

Names used for Pacific populations added a twist. Researchers compared specimens then called A. moseri (Hawai‘i), A. mordens (Australia), and A. alata (Bonaire). Their 2016 analysis found shared genetic patterns and no clear species boundary among those sampled populations, and treated A. moseri and A. mordens as junior synonyms of the older name A. alata.^[1] The current World Register of Marine Species lists those names under A. alata, while recognizing other named Alatina species separately.^[3]

This was not a finding that every jellyfish in the genus is the same species. It was a conclusion about the populations and names examined, using the evidence available to that study. More sampling—especially across the Caribbean and other tropical regions—could refine the picture.

Where has Alatina alata been documented?

Strongly documented reproductive populations include Bonaire in the Caribbean, O‘ahu in Hawai‘i, and Osprey Reef off Queensland, Australia. The 2016 study compared specimens from those places under the names A. alata, A. moseri, and A. mordens; it also included an Alatina specimen from Saipan that the authors left as Alatina sp. rather than assigning confidently to this species. Several genetic markers supported close relationships among the named populations, but the study did not sample every tropical coastline or prove continuous occupancy between sites.^[1]

It is an oceanic animal, not simply a jellyfish that lives at the waterline. Museum specimens and archived observations include open-water and deep-water records; the Bonaire redescription documented material from surface waters to 675 metres, and reviewed additional Atlantic reports from deeper water.^[2] These records show how far from shore the species may occur, but they do not tell us how often it occupies a particular depth.

Because the most predictable encounters occur during local reproductive swarms, the general species profile should not replace local conditions. For Hawai‘i-specific timing and beach context, see our Hawaiian box jellyfish guide; for the broader behavior across species, see how lunar-period box jellyfish aggregations are studied.

How the lunar spawning sequence works

The phrase “moon jellyfish” can make the event sound like a simple response to a bright full moon. The evidence is subtler. A 2022 Hawai‘i study analyzed 14 years of shoreline counts and combined them with reproductive examinations and nighttime ship surveys. On O‘ahu, mature adults were observed swimming shoreward before moonrise during the recurring post-full-moon window. The authors found a relationship between the duration of darkness and migration timing, but described the proposed cue as a hypothesis—not a mechanism proven by experiment.^[4]

1. Mature adults gather in the local window. Reproductive swarms have been observed around 8–10 days after full moon at Bonaire, Hawai‘i, and Australian sites. A calendar date predicts neither the presence of animals at every beach nor safety conditions there.^[1]
2. Some adults move shoreward. In O‘ahu nighttime transects, researchers saw adult animals swimming toward shore; observations and beach counts document the Hawaiian pattern, not a universal route shared by every population.^[4]
3. Adults aggregate and become reproductively active. Bonaire researchers collected adults during local swarms and documented mature gonads and post-spawning material. Reproductive observations at one site do not establish an identical sequence or timing at all sites.^[2]
4. Sperm transfer is not simply a cloud of eggs and sperm released together. In the described process, males release sperm into the water; females take it up, and fertilization is internal. This is called spermcasting. It differs from the familiar coral-style broadcast spawning image.^[1]
5. Embryos develop into larvae; later stages are harder to observe in nature. Researchers have reared early stages in laboratory settings, including planula larvae. The complete timing, settlement sites, and survival of every wild cohort are much less directly observed than the adult swarms.^[2][5]

Important distinction: “8–10 days after the full moon” is a recurring observation from particular study localities, not a prediction service. In Hawai‘i, counts and ship observations show the event’s timing; they do not prove that the visible lunar phase itself is the biological trigger. For general moon-phase and migration context, our lunar migration explainer separates the different cues and the limits of the evidence.

What is known—and not known—about Alatina alata stings?

A. alata has stinging cells and can cause painful contact. A small body of clinical research exists from Waikīkī, Hawai‘i, where papers published in 2001 referred to the local animal as Carybdea alata. One randomized beach study compared several topical approaches with seawater for pain after these stings; it was a local treatment study, not a global study of severity, fatality, or risk across all Alatina populations.^[6]

That distinction matters. The older names used in clinical papers predate the later taxonomic work, and a Waikīkī study cannot establish how often severe outcomes occur elsewhere. We did not find a reliable species-wide rate for severe injury or death in the primary sources reviewed. If a sting occurs, follow lifeguard and local emergency-service instructions; seek urgent professional help for severe or worsening symptoms. Do not enter a jellyfish aggregation or handle stranded animals.

What scientists still do not know

• The exact lunar cue: darkness duration, moonrise, tides, currents, or interacting conditions may matter. O‘ahu correlations are informative, but they do not by themselves prove cause.^[4]
• The full geographic range: molecular comparisons support a broad tropical distribution, but many regions have not been sampled with comparable genetic and morphological methods.^[1]
• Population connectivity: the genetic study found shared haplotypes and little clear geographic separation in several markers, alongside some structure. It could not determine whether movement between ocean basins is natural, historical, or ongoing.^[1]
• Most of the animal’s year: adult swarms are conspicuous, while where individuals spend the rest of the time is much less well documented.^[1]
• Global sting outcomes: local clinical observations do not provide a reliable species-wide estimate of how frequently stings become medically serious.

These gaps are not footnotes to the story—they are why careful specimen records, genetic vouchers, and dated local observations matter. For more on how scientists distinguish named species, see our guide to box jellyfish classification and the box jellyfish species directory.

Research sources

1. Lawley, J.W. et al. (2016). “Box Jellyfish Alatina alata Has a Circumtropical Distribution.” Biological Bulletin. Population-genetic, taxonomy, range, and reproduction evidence.
2. Lewis, C. et al. (2013). “Redescription of Alatina alata (Reynaud, 1830) from Bonaire, Dutch Caribbean.” Zootaxa 3737: 473–487.
3. World Register of Marine Species: Alatina alata taxon record. Current accepted name and synonym record, checked 3 November 2026.
4. Yanagihara, A.A. et al. (2022). “Alatina alata box jellyfish monthly migrations in Hawai‘i: Lunar and physical oceanographic triggers.” Regional Studies in Marine Science 52: 102380.
5. Carrette, T., Straehler-Pohl, I. & Seymour, J. (2014). “Early Life History of Alatina cf. moseri Populations from Australia and Hawaii with Implications for Taxonomy.” PLoS ONE 9(1): e84377.
6. Thomas, C.S. et al. (2001). “Box jellyfish (Carybdea alata) in Waikiki: their influx cycle plus the analgesic effect of hot and cold packs on their stings to swimmers at the beach.” Hawaii Medical Journal 60(4): 100–107. Local clinical evidence; not a global estimate of sting severity.