Pteropods are tiny marine mollusks separated into two groups, the sea butterflies (clade Thecosomata) and the sea angels (clade Gymnosomata). Sea butterflies develop shells, but sea angels do not. These tiny gastropods are such a major dietary staple of larger marine species, they are affectionately deemed the potato chips of the sea.

Photo courtesy of NOAA

Over the past decade, the problem of invasive species has become more pervasive in aquatic systems around the globe. With the continued warming of water bodies due to climate change, dangerous invasives can expand their ranges and invade established habitats.

A notable example of this is the Humboldt squid, also called the jumbo squid (Dosidicus gigas), moving all the way up the Pacific coast from Mexican waters to as far north as the coast of Vancouver Island. One of the most powerful ways the species disrupts the ecosystem is that it consumes tremendous amounts of prey. Humboldt squids grow to be over 1.5 m in length and an average of 50 kg (100 lbs) in under one year; this necessitates that the squid feeds constantly, which annihilates prey species in the Humboldt’s range. Because many of its prey items are economically important fishes, the expansion and actions of the Humboldt squid are being avidly monitored.

Photo © Brian Skerry

The ornate cowfish (Aracana ornata), like all cowfish, has a skeleton made of fused bones, essentially trapping it in a barely-flexible box. For this reason, these fish are typically slow movers; however, it does have an advantage: few other fish are able to eat adult cowfish.

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Jewel moray (Muraena lentiginosa)

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Viper Moray (Enchelynassa canina), particularly well known for its fierce set of teeth.

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Snowflake eel (Echidna nebulosa)

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Chain Moray (Echidna catenata)

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Banded creeping eel (Channomuraena vittata)

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Marbled reef eel (Anarchias seychellensis)

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Hardtail Moray Eel (Anarchias galapagensis)

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