Two new brackish-water species of Testudinella (Rotifera: Testudinellidae) from Qi’ao Island in the Pearl River estuary, China, with a key to marine and brackish-water Testudinella Author Wei, Nan Author De, Willem H. Author Xu, Runlin text Zootaxa 2011 3051 41 56 journal article 46222 10.5281/zenodo.207785 ae05f614-8db9-4cd5-adb1-6f2d4ac83651 1175-5326 207785 Key to marine and brackish-water species of Testudinella 1 Foot opening circular or semi-circular.................................................................... 2 - Foot opening a more or less wide, inverted U-shaped slit..................................................... 3 2(1) Foot opening circular, situated near centre or slightly posterior to centre of lorica; lorica almost circular; antero-ventral margin with median sinus; antero-dorsal margin almost straight to weakly convex, or three more or less pronounced shallow lobes.................................................................................. T. patina (Hermann, 1783) - Foot opening semi-lunar, almost terminally; lorica elliptical; antero-dorsal margin convex, antero-ventral margin with broad Vshaped sinus.................................................................. T. elliptica (Ehrenberg, 1834) 3(1) Antero-ventral margin with median sinus bordered by two more or less acute projections........................... 4 - Antero-ventral margin almost straight or with median sinus not bordered by acute projections........................ 5 4(3) Antero-dorsal margin convex without median sinus; lorica in cross-section asymmetrical dorsally and ventrally, with arched dorsal margin and smaller ventral margin delimited by rounded lateral margins, not particularly compressed....................................................................................... T. crassa (Levander, 1894) sp. inq. - Antero-dorsal margin with median sinus; lorica in cross section symmetrical both dorsally and ventrally, with rounded lateral margins, distinctly compressed dorso-ventrally............................................ T. dentata Myers, 1934 5(3) Lorica strongly elongate, ratio length/width> 2.2; antero-ventral margin almost straight, antero-dorsal margin tripartite, with median part and two lateral parts.................................................... T. elongata De Smet, 2009 - Lorica not strongly elongate, ratio length/width <1.8; antero-ventral margin with distinct median sinus, antero-dorsal margin convex, or with median sinus, or tripartite................................................................. 6 6(5) Both antero-dorsal and antero-ventral margin with median sinus or indentation..................................... 7 - Only antero-ventral margin with median sinus or indentation................................................... 8 7(6) Antero-dorsal and antero-ventral margin with broad median sinus; two acute antero-lateral projections............................................................................................... T. bicorniculata De Smet, 2009 - Antero-ventral margin with broad median sinus, antero-dorsal margin with small median indentation; antero-lateral projections absent............................................................................. T. quadrilobata sp. nov. 8(6) Antero-dorsal margin convex........................................................ T. clypeata (Müller, 1786) - Antero-dorsal margin tripartite, with median flat or slightly convex part and two lateral parts, whether or not connected by shallow folds......................................................................................... 9 9(8) Lorica more or less elliptical, weakly truncate anteriorly; in cross-section lateral edges converging to a sharp angle; major unci teeth with more or less strongly club-shaped head; minor unci teeth parallel, rake-like............ T. obscura Althaus, 1957 - Lorica vase-shaped, distinctly truncate anteriorly; in cross section lateral edges broadly rounded; major unci teeth lanceolate; minor teeth not parallel, not rake-like..................................................................... 10 10(9) Lorica in cross-section almost symmetrical both dorsally and ventrally, more or less cruciform with broadly rounded lateral edges and rounded dorsal and ventral median part; rami with stout, quadratic alulae.................................................................................................... T. zhujiangensis Wei, De Smet & Xu, 2010 - Lorica in cross-section asymmetrical dorsally and ventrally, not cruciform, with arched dorsal margin, lateral edges broadly rounded delimiting a smaller, weakly convex median part ventrally; rami with weakly developed, more or less spiniform alulae................................................................................. T. pseudobscura sp. nov.