Kaleidoscope Jellyfish (Haliclystus auricula)
Key Details
| Taxonomic Groups: | Invertebrate > coelenterate (=cnidarian) > Cnidarian |
| Red List Status: | (Not Relevant) [(not listed)(nr)] |
| D5 Status: | |
| Section 41 Status: | (not listed) |
| Taxa Included Synonym: | (none) |
| UKSI Recommended Name: | Haliclystus auricula |
| UKSI Recommended Authority: | (Rathke, 1806) |
| UKSI Recommended Qualifier: | s.lat. |
| Red List Citation: | (not listed) |
| Notes on taxonomy/listing: | (none) |
Criteria
| Question 1: | Does species need conservation or recovery in England? |
| Response: | Yes |
| Justification: | Considered rare, since the 1960s and 70s there have been population declines, with individuals rarely found where they were once abundant. Although there has been recent (2010-2019) increases in sightings these are lower than earlier levels. The trend, whether these are part of normal fluctuations and reasons behind decline are unclear. |
| Question 2: | Does recovery/ conservation depend on species-specific actions? |
| Response: | Yes |
| Justification: | Historically known from the East Anglian fens and the Norfolk Broads, but declined during the 19th century and was not recorded in East Anglia after 1910. A population was discovered in the New Forest in 1969, but there have been no further records since 1973 despite intensive targeted searches of this locality. It is considered a relatively easy species to find in suitable habitat. Within the British range there may no longer be any recently cut-over bogs, or early-successional raised bogs to provide suitable habitat and thus the species is probably extinct in Britain. It is present in Northern Ireland. On this basis the species is not considered suitable for recovery actions. |
| Question 3: | At a landscape scale, would the species benefit from untargeted habitat management to increase habitat mosaics, structural diversity, or particular successional stages? |
| Response: | No |
| Justification: | Not relevant to marine species |
Species Assessment
| Current step on the Species Recovery Curve (SRC): | 3. National Monitoring Plan agreed and implemented |
| Recovery potential/expectation: | Unknown |
| National Monitoring Resource: | Opportunistic - insufficient |
| Species Comments: | There is very little evidence for pressure impacts and little on the autoecology, population dynamics and trends. This species occurs on vegetation in the lower intertidal and subtidal, with seagrass and seaweeds being used. Vegetated habitats are therefore considered critical habitat and are common and widespread. |
Key Actions
Key Action 1
Proposed Action: Develop an effective monitoring protocol and census and monitor populations at key sites.
Action targets: 3. National Monitoring Plan agreed and implemented
Action type: Targeted monitoring
Duration: >10 years
Scale of Implementation: ≤ 50 sites
High priority sites: Sites of former occupation or where this species is known to occur, south east England and the south west where it was studied extensively by P. Corbin 1950s-1970s
Comments: Monitoring should be focussed on known existing populations, particularly within MPAs, as a part of site management. Also targeted surveys at known former sites. Surveys within protected areas could form part of 6-year monitoring and could monitor for additional stalked jellyfish and other key species (including seagrass). Citizen scientists could potentially be used as the species occurs in shallow waters, is large enough to be seen (2-2.5cm) and is distinctive.
Key Action 2
Proposed Action: Develop a research proposal to understand ecology and drivers of change.
Action targets: 4. Autecology and pressures understood
Action type: Scientific research
Duration: 3-5 years
Scale of Implementation: Not applicable
High priority sites: Informed by monitoring, disparate study sites and lab research required.
Comments: Further research is required to understand ecology and factors that influence their appearance and disappearance. There is very limited knowledge of the biology and ecology of this species (particularly reproductive strategy and minimum viable population level), its full distribution, and what is most effecting its survival/ apparent decline. Recovery may be successful via re-introduction of breeding populations but understanding of reproduction and development of captive breeding is first necessary. Understanding of conditions for successful breeding and rearing are of wider interest/significance.
Key Action 3
Proposed Action: Promotion of the group, encouraging increased awareness, recording and monitoring, and studying patterns of behaviour and factors that influence their appearance and disappearance.
Action targets: 5. Remedial action identified
Action type: Education/awareness raising
Duration: 3-5 years
Scale of Implementation: National
High priority sites: Sites and stakeholders identified from first two actions.
Comments: General awareness raising may increase reporting, monitoring and action to reduce any identified pressure. Action can apply to all stalked jellyfish.
Acknowledgment:
Data used on this website are adapted from Threatened species recovery actions 2025 baseline (JP065): Technical report and spreadsheet user guide (Natural England, 2025). Available here.