Echinolittorina placida Reid, 2009 Interrupted Periwinkle

    Only recently described (Reid, 2009: 56), this species has a zoogeographic history unparalleled among benthic marine snails. Its stunningly exploitative range extension, beginning in a small area of sparse rocky outcrops of the southeastern Gulf of Mexico and moving 4,500 km around the Gulf of Mexico to Florida and as far as North Carolina, spans just one century! Some of us Florida collectors had noted there was an historical disconnect in the composition, zoogeography, and population densities of our periwinkle fauna just in the last few decades. As we struggled to pigeonhole the newcomer using a variety of incorrect names, most notably E. interrupta (Philippi, 1856), we sent specimens to Dr. Reid, who kept us abreast of his work as it progressed.

    Over several years Reid verified and pieced together collection data and literature records to support the geographic and chronologic progress of this speedy invasion. He reasoned that widespread construction of sea walls, jetties, etc. along the otherwise soft sedimentary coastline of the Gulf of Mexico since the late nineteenth century, facilitated this range expansion by providing suitable habitat (hard intertidal substrate) where none existed historically. Although the majority of localities cited by Dr. Reid were based on public museum specimens, the collections of Florida amateurs, including our group and Marlo Krisberg, played a role in the reconstruction of this saga.

    Besides providing readers with a chronicle of colonization of a marine intertidal habitat of arguably unprecedented dimensions, this fine work once again demonstrated the importance of well-curated collections of citizen scientists in the recognition and definition of biological processes - in this case a breathtaking large-scale one.

Reid, D.G., 2009. The genus Echinolittorina Habe, 1956 (Gastropoda: Littorinidae) in the western Atlantic Ocean. Zootaxa 2184: 1­103. Aug. 6. Abstract at <http://www.mapress.com/zootaxa/2009/f/z02184p103f.pdf>