Hitch-Hiking Beaver Spotted Napping Atop Humpback Whale

by Natalie Sopinka—AFS Contributing Writer [email protected]

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Broken-rays mussel Lampsilis reeveiana. Photo credit: Chris Barnhart, Missouri State University

Perhaps exhausted after a long-distance swim along the St. Lawrence River, a beaver was seen sleeping on the back of a humpback whale Megaptera novaeangliae in the Bay of Fundy. Upon closer inspection of the whale (which was likely demonstrating logging behaviour and remaining still at the surface), quiet snores could be heard from the snoozing beaver. April Fools! April 1st is the day of the year traditionally reserved for silly jokes and playful pranks. In France, the first day of April is celebrated as Poisson d’Avril which translates to April Fish. The customary trick of Poisson d’Avril is trying to [su_members message=”This content is for members only. Please login.”

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   login_url=”/membership/member-login/” class=””]stick a cardboard fish on the back of an unsuspecting friend. While we humans play tricks on land, aquatic creatures are playing tricks too.

LEAFY SEADRAGON The mood is quite peaceful among the wavy strands of seaweed swaying gracefully under the command of Australia’s currents. Slowly fluttering, the delicate leaves feed on tiny mysid shrimp (Order Mysida). Shrimp-eating seaweed? Surprise! You have been duped by the Leafy Seadragon Phycodurus eques. A relative of seahorses Hippocampus spp., the Leafy Seadragon has numerous leaf-like appendages growing from its body. The elaborate, seaweed-mimicking extensions provide remarkable camouflage. Leafy Seadragons also have cryptic markings on their snouts. These unique facial patterns can be used for individual identification (Connolly et al. 2002).

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Leafy Seadragon Phycodurus eques. Photo credit: Christian Loader.

BROKEN RAYS MUSSEL The broken-rays mussel Lampsilis reeveiana is an exceptional trickster. The two flaps extending from the mussel’s mantle are colored, shaped, and move like a small fish. Don’t be fooled, this teleost imposter is actually a balloon filled with larval mussels (glochidia) that bursts when an unsuspecting bass takes a bite. A flurry of parasitic larvae are freed and affix to the gills of their piscivorous host (Barnhart and Roberts 1997).   REFERENCES Barnhart, M. C., and A. D. Roberts. 1997. Reproduction and fish hosts of unionids from the Ozark Uplifts. Pages 14–20 in K. S. Cummings, A. C. Buchanan, L. M. Koch, editors. Conservation and management of freshwater mussels II. Proceedings of a UMRCC symposium. Upper Mississippi River Conservation Committee, Rock Island, Illinois. Connolly, R. M., A. J. Melville, and J. K. Keesing. 2002. Abundance, movement and individual identification of Leafy Seadragons, Phycodurus eques (Pisces: Syngnathidae). Marine and Freshwater Research 53(4):777–780 TO CITE THIS ARTICLE Natalie Sopinka (2015) Hitch-Hiking Beaver Spotted Napping Atop Humpback Whale, Fisheries, 40:4, 187-187, DOI: 10.1080/03632415.2015.1018382 [/su_members]