bulldogskjell
CR

bulldogskjell

Macandrevia cranium

Unknown

Photo: iNaturalist: (c) Amphibol, some rights reserved (CC BY-SA)

Overview

The bulldogskjell (Macandrevia cranium) is a distinctive deep-sea brachiopod characterized by its robust, skull-like shell with pronounced ridges and a broad, flattened profile reminiscent of a bulldog's face. This sessile filter-feeder plays a crucial role in benthic ecosystems by processing organic matter from the water column and providing hard substrate for other marine organisms to colonize.

The bulldogskjell (Macandrevia cranium) faces severe population decline primarily due to deep-sea trawling activities that destroy its fragile cold-water coral reef habitat. Climate change-induced ocean acidification and warming temperatures further threaten the species by degrading the calcium carbonate structures it depends on for survival. The species' extremely limited range and slow reproductive rate make recovery particularly challenging.

Threat summary

Habitat

Macandrevia cranium inhabits cold, deep continental shelf waters between 200-800 meters depth, typically anchoring to rocky outcrops and stable sediment areas with strong bottom currents. The species requires low-temperature environments with high dissolved oxygen levels and specific calcium carbonate saturation conditions found along northern Atlantic and Pacific continental margins.

MARINE· major

Threatened in Antarctica

Chilean FlamingoVU

Chilean Flamingo

Phoenicopterus chilensis

Unknown
Tall Sea PenVU

Tall Sea Pen

Funiculina quadrangularis

Unknown
VU

Ophiura robusta

Unknown
VU

Champsocephalus esox

Declining

Frequently asked questions

Why is bulldogskjell classified as Critically Endangered?
bulldogskjell is classified as Critically Endangered — facing an extremely high risk of extinction in the wild — because population sizes are very small, declining sharply, or restricted to a tiny range. The bulldogskjell (Macandrevia cranium) faces severe population decline primarily due to deep-sea trawling activities that destroy its fragile cold-water coral reef habitat. Climate change-induced ocean acidification and warming temperatures further threaten the species by degrading the calcium carbonate structures it depends on for survival. The species' extremely limited range and slow reproductive rate make recovery particularly challenging.
Where does bulldogskjell live?
bulldogskjell occurs in Antarctica, Canada, Chile, Denmark, Faroe Islands, and France (plus 13 other countries). Country-level distribution data is sourced from the IUCN Red List and cross-referenced with GBIF occurrences.
What are the main threats to bulldogskjell?
The main threats to bulldogskjell are ai-1, ai-2, ai-3, and ai-4. The full IUCN-classified threat record for this species is detailed on the species page.

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