Abstract
Eurytemora carolleeae sp. nov. (Crustacea: Copepoda: Calaniformes) is described from the Chesapeake Bay, USA. The new species belongs to the Atlantic clade of the Eurytemora affinis complex outlined by previously published molecular work but poorly characterized morphologically. To discriminate E. carolleeae we compare specimens from the Atlantic USA clade with specimens from the type population of E. affinis (Poppe, 1880) from the Elbe River Estuary (Germany), as well as with eight other European coastal populations. Several important morphological characters clearly separate the North American E. cf. affinis from the European clade that include both sexes: a large outside orientated dent on the mandible, and clearly observable seta segmentation in the caudal rami and swimming legs. Unlike E. affinis, the newly described species possesses wing-like outgrowths on the genital double-somite and a very small spine near the distal seta insertion point in P5 in females. In males, the specific characters include naked dorsal and ventral sides of the caudal rami, and a cylindrical shape of exopod on the left P5, in contrast to a triangular shape of the segment in E. affinis. The new species was also found in Canada (St. Lawrence Estuary) and as an invasive species in the Baltic Sea. Eurytemora carolleeae is possibly widely distributed along the North American Atlantic coast, as well as in inland waters from Great Lakes to Mexico.References
Albaina, A., Villate, F. & Uriarte, I. (2009) Zooplankton communities in two contrasting Basque estuaries (1999–2001): reporting changes associated with ecosystem health. Journal of Plankton Research, 31, 739–752.
Alekseev, V.R., Abramson, N.I. & Sukhikh, N.M. (2009) Introduction of Sibling Species to the Ecosystem of the Baltic Sea. Doklady Biological Sciences, 429, 1–4.
Busch, A. & Brenning, U. (1992) Studies on the status of Eurytemora affinis (Poppe, 1880) (Copepoda, Calanoida). Crustaceana, 62, 13–38.
Croskery, P. (1978) The freshwater co-occurrence of Eurytemora affinis (Copepoda: Calanoida) and Manayunkia speciosa (Annelida: Polychaeta): possible relicts of a marine incursion. Hydrobiologia, 59, 237–241.
Debiase, A.E. & Taylor, B.E. (1993) New occurrences of Eurytemora affinis and Epischura fluviatilis, freshwater calanoid copepod species of the family Temoridae, in South Carolina. The American Midland Naturalist, 130, 386–392.
Dodson, S.I., Skelly, D.A. & Lee, C.E. (2010) Out of Alaska: Morphological evolution and diversity within the genus Eurytemora from its ancestral range (Crustacea, Copepoda). In: L. Naselli-Flores & G. Rossetti (Eds.) Fifty years after the “Homage to Santa Rosalia”: Old and new paradigms on biodiversity in aquatic ecosystems. Hydrobiologia, 653, 131–148.
Dussart, B. (1967) Les Copépodes des eaux continentales d'Europe occidentale. Tome I: Calanoïdes et Harpacticoïdes. N. Boubée et Cie, Paris, 500 pp.
Dussart, B. & Defaye, D. (2002) World directory of Crustacea Copepoda of inland waters. I – Calaniformes. Backhuys Publishers, Leiden, 276 pp.
Huys, R. & Boxshall, G.A. (1991) Copepod evolution. The Ray Society, London, 468 pp.
Knowlton, N. (1993) Sibling species in the sea. Annual Revue Evolution and Systematics, 24, 189–216.
Lee, C.E. (1999) Rapid and repeated invasions of fresh water by the copepod Eurytemora affinis. Evolution, 53, 1423–1434.
Lee, C.E. (2000) Global phylogeography of a cryptic copepod species complex and reproductive isolation between genetically proximate “populations”. Evolution, 54, 2014–2027.
Lee, C.E. & Frost, B.W. (2002) Morphological stasis in the Eurytemora affinis species complex (Copepoda: Temoridae). Hydrobiologia, 480, 111–128.
Lee, C.E. & Petersen, C.H. (2003) Effects of environmental acclimatization on adult salinity tolerance in the freshwater invading copepod Eurytemora affinis. Physiological and Biochemical Zoology, 76, 296–301.
Poppe, S.A. (1880) Über eine neue Art calaniden Gattung Temora Baird. Naturwasser Verhart Bremen, 7, 55–60.
Rylov, V.M. (1922) On new species Copepoda–Calanoida. Proceedings of Sain–Petersburg Society of Naturilists, 52, 67–78. [in Russian]
Souissi, A., Souissi, S., Devreker, D. & Hwang, J.S. (2010) Occurrence of intersexuality in a laboratory culture of the copepod Eurytemora affinis from the Seine estuary (France). Marine Biology, 157, 851–861.
Suáres-Morales, E. & Reid, J.W. (1994) Adiciones a la fauna plánctica de aguas continentales de Quintana Roo, México. AvaCient Chetumal, 9, 29–33.
Suáres-Morales, E. & Reid, J.W. (1998) An updated list of the free living freshwater copepods (Crustacea) of Mexico. The Southwestern Naturalist, 43, 256–265.
Suáres-Morales, E., Reid, J.W. & Gasca, R. (2000) Free-living marine and freshwater Copepoda (Crustacea) from Mexico. In: J. Llorente, E. Gonzalez & N. Papavero (Eds.), Biodiversidad, taxonomía y biogeografía de Artrópodos de México. Hacia una síntesis de su conocimiento, 2, CONABIO & UNAM, Mexico, pp. 171–190.
Suáres-Morales, E., Rodrigues-Almaraz, G., Gutierrez-Aguippe, M.A. & Walsh, E. (2008) The coastal-estuarine copepod, Eurytemora affinis, (POPPE) (CALANOIDA, TEMORIDAE), from arid inland areas of Mexico: an expected occurrence? Crustaceana, 81, 679–694.
Telesh, I. & Heerkloss, R. (2004) Atlas of estuarine zooplankton of the southern and eastern Baltic sea. Part II: Crustacea. Verlag Dr. Kovac, Hamburg, 118 pp.