A revision of Eogammarus Birstein, 1933 (Crustacea, Amphipoda, Anisogammaridae), with a description of a new species Author Tomikawa, Ko Author Morino, Hiroshi Author Toft, Jason Author Mawatari, Shunsuke F. text Journal of Natural History 2006 J. Nat. Hist. 2006-08-28 40 17 - 18 1083 1148 http://dx.doi.org/10.1080/00222930600828859 journal article 10.1080/00222930600828859 1464-5262 41F5583D-BD6D-4FFF-961F-39AA6A6ECCE8 Key to the species of Eogammarus 1. Urosomite 2 with four clusters of robust setae........... 2 – Urosomite 2 with two clusters of robust setae........... 3 2. Posterior margin of peduncular articles 4 and 5 each with 0–1 setal pair or cluster. Telson as long as wide.............. E. turgimanus – Posterior margin of peduncular articles 4 and 5 each with 2–6 setal pairs or clusters. Telson longer than wide.............. E. ryotoensis 3. Pereopods 3–7 with numerous plumose setae. Ventral margin of epimera 2 and 3 with numerous plumose setae. Retinacula on pleopods triplicated..... 4 – Pereopods 3–7 with simple setae. Ventral margin of epimera 2 and 3 with simple setae. Retinacula on pleopods paired.............. 5 4. Aesthetascs on antenna 1 shorter than surrounding setae. Calceoli on antenna 2 wider than 0.25× width of respective flagellar article.... E. psammophilus – Aesthetascs on antenna 1 longer than surrounding setae. Calceoli on antenna 2 narrower than 0.25× width of respective flagellar article..... E. schmidti 5. Peduncular article 1 of antenna 2 lacking robust setae. Outer margin on palp article 1 of maxilla 1 with setae................. 6 – Peduncular article 1 of antenna 2 with robust setae. Outer margin on palp article 1 of maxilla 1 lacking setae................ 10 6. Pleonites dorsally carinate.............. E. tiuschovi – Pleonites dorsally smooth................. 7 7. Peduncular article 1 of antenna 1 with slender posterodistal seta. Posterior setae on bases of pereopods 6 and 7 shorter than half width of ischium. Ventral margins of epimera 2 and 3 with robust setae only.......... E. possjeticus – Peduncular article 1 of antenna 1 with robust posterodistal seta. Posterior setae on bases of pereopods 6 and 7 longer than half width of ischium. Ventral margins of epimera 2 and 3 with slender or slender+robust setae......... 8 8. Flagellar articles on antenna 1 each with two aesthetascs.... E. itotomikoae – Flagellar articles on antenna 1 each with one aesthetasc........ 9 9. Longest posterior seta on basis of male pereopod 7 shorter than width of ischium. Robust apical setae on telson shorter than slender apical setae.... E. kygi – Longest posterior seta on basis of male pereopod 7 longer than width of ischium. Robust apical setae on telson longer than slender apical setae... E. barbatus 10. Antenna 2 of female with calceoli. Robust apical setae on telson shorter than slender apical setae or as long as slender apical setae..... E. confervicolus – Antenna 2 of female lacking calceoli. Robust apical setae on telson longer than slender apical setae................. E. oclairi