In the translucent depths of British Columbia’s coastal and offshore waters, one of the more beguiling – and least understood – marine creatures plies its silent existence: the comb jelly, or ctenophore. For many beachgoers and divers, these organisms appear only fleetingly as shimmering, rainbow-prismatic shapes drifting by, their presence betrayed by the subtle flicker of light along rows of beating cilia.
Though they superficially resemble jellyfish, comb jellies are taxonomically distinct: they belong to the phylum Ctenophora, not to the Cnidaria (the group that includes “true” jellies, corals and sea anemones).
In the Pacific Northwest, including British Columbia and the Salish Sea region, fewer than 30 species of comb jellies are reliably recorded. Their relative scarcity in identification guides and public awareness belies the ecological importance they may play – particularly in planktonic food webs.
Photo by iStockAnatomy, Movement & Feeding: Elegant Simplicity
What makes comb jellies striking – and visually arresting – is their mode of locomotion and nearly ethereal appearance.
The “combs” and the light show: Each comb jelly carries eight longitudinal rows (comb rows or ctenes) of fused cilia (hair-like structures). These ctenes beat in synchrony, propelling the organism with a subtle, gliding motion. When light (sunlight or artificial) strikes these beating combs, it refracts, producing the characteristic rainbow shimmer that can make a comb jelly appear as though sporting a living aurora.
Body plan and prey capture: The body is essentially a gelatinous, nearly transparent envelope with an inner canal system and a mouth (or mouths) for ingestion. Many ctenophores bear colloblasts – adhesive cells that capture prey by sticking to them, rather than stinging (as jellyfish do).
Some types (the tentaculate ctenophores) have tentacles with colloblasts, while others (the nuda) lack tentacles and swallow prey whole (often smaller comb jellies).
In BC waters, prominent genera include Pleurobrachia (sea gooseberries), Bolinopsis (lobed comb jellies) and Beroe (predatory on other ctenophores).
Mobility, fragility and behaviour: Because of their delicate bodies, comb jellies are extremely sensitive to turbulence and handling – they often break apart if disturbed too quickly. In captivity, they must be moved with glacial slowness (for instance, coaxed into beakers rather than scooped).
Some species also engage in vertical migrations or drift with water layers, optimizing their foraging in productive plankton-rich zones.
Comb Jellies Along British Columbia’s Coast: Local Species & Observations
In the Salish Sea and adjacent waters:
- Sea Gooseberry (Pleurobrachia bachei): Small (a few millimetres to about 15mm), common in nearshore plankton.
- Lobed Comb Jelly (Bolinopsis infundibulum): Up to about 15cm in length, with broad lobes and comb rows; encountered from surface to deeper zones.
- Beroid comb jellies (e.g. Beroe abyssicola) are also noted in local literature, sometimes referred to in Victoria-area marine life guides.
There are also reports – often from community science, beachcombing or social media posts – of more elongated “cigar-shaped” ctenophores washed ashore, possibly in the genus Beroe.
Because of their transparency and fragility, many sightings go unnoticed or unrecognized. Even when washed ashore, their delicate bodies may degrade rapidly. Observers sometimes mistake them for non-living jellylike matter. A beach find in Tofino was identified by the local community as a comb jelly based on its characteristic longitudinal lines.
Seasonal & Environmental Factors
Comb jellies in BC are likely more abundant during spring and early summer, coinciding with plankton blooms (their prey base). They might also be more visible in calm, clear water conditions where light penetration allows their shimmering rows to be seen.
Environmental stressors – such as temperature shifts, salinity variation (from freshwater runoff) or turbulence – can affect their distribution and survival, though specific studies for BC are limited.
Photo by iStockEcological Role: Plankton Predators & Prey
Though often overlooked, comb jellies can exert outsized influence in planktonic ecosystems:
- Plankton regulation: By preying on copepods, small crustaceans, larval fish and other zooplankton, they help modulate lower trophic levels, potentially influencing the recruitment success of fish or shellfish species.
- Trophic connectivity: Comb jellies may themselves be prey for larger predators (fish, sea turtles in other regions), linking gelatinous realms to higher trophic levels.
- Predator-on-predator: Some ctenophores (like Beroe species) prey on other comb jellies, acting as top comb-jelly predators and adding complexity to gelatinous food webs.
Because of their often cryptic nature, the quantitative role of comb jellies in BC’s coastal ecosystems remains underexplored. But globally, ctenophores are recognized as important components of the “jelly web” in many marine systems.
Challenges, Research Gaps & Discoveries
Fragility and sampling difficulty: Their delicate structure makes sampling without damage a challenge, particularly for deep or high-current zones. Many specimens degrade before identification, inhibiting taxonomy and population studies.
Taxonomy, cryptic diversity and molecular methods: Because morphological differences are subtle, molecular (genetic) techniques are now being applied to reveal hidden species diversity and relationships. In many marine regions globally, cryptic ctenophore diversity is being uncovered.
Deep-sea ctenophores and pressure adaptations: Recent research (not specific to BC) has revealed that deep-sea ctenophores possess lipid adaptations that help their cell membranes remain functional under extreme pressure, a phenomenon known as homeocurvature (an analog to homeoviscous adaptation in cold-adapted lipids).
This points to the potential for undiscovered, pressure-adapted ctenophore species off British Columbia’s deep continental slopes or seamount systems.
Fossil Legacy – BC’s Ancient Comb Jellies
Interestingly, British Columbia also figures in the deep history of ctenophores. The Burgess Shale (in BC) has yielded fossil comb jellies such as Ctenorhabdotus capulus and Fasciculus vesanus, with 24 comb rows – far more than modern ctenophores. The extinct genus Xanioascus canadensis is also known from BC. These fossils illustrate how ctenophore lineages have evolved drastically through geological time.
Why They Matter To BC: Conservation & Public Interest
Though comb jellies rarely headline marine conservation policy, their presence (or absence) can serve as subtle indicators of plankton ecosystem health, water clarity and oceanographic changes. As climate change, stratification, and eutrophication alter plankton communities, ctenophore populations may respond in detectable ways.
Increasingly, aquaria in BC (such as the Ucluelet Aquarium) may inadvertently host larval or small planktonic ctenophores due to their seawater intake systems, offering opportunities for public education and informal observation.
Citizen scientists and beachcombers can help, too: documenting rare beach strandings, photographing specimens with scale and detail (e.g. showing comb row lines) and preserving tiny samples (if possible) for specialists.
A Glimpse Into The Invisible Ballet
To stand by a calm inlet in BC at twilight and watch the water glint with shifting, living filaments is to glimpse the faint signature of comb jellies. They are dancers in an unseen ballet, moving with poetic slowness, feeding on microscopic worlds and weaving through a realm we barely perceive.
Their beauty belies a complexity and ecological subtlety that scientists are only beginning to appreciate. For British Columbia – with its deep channels, fjords, nutrient fluxes and human pressures – comb jellies are participants in the grand marine symphony. The more we research, document and preserve their habitats, the more we will understand not only the lives of these ghostly creatures, but the pulse and balance of sea life around us.
