Tonicia, Gray, 1847

Sirenko, B. I. & Ibáñez, C. M., 2023, Comparative morphology of Tonicia (Polyplacophora) geographical ecotypes from Southeastern Pacific, Ruthenica, Russian Malacological Journal (Cambridge, England: 2003) 33 (1), pp. 27-45 : 37-38

Taxonomic key for identification of species and ecotypes of genus Tonicia from Southeastern Pacific

1(2) Girdle connects between valves. Cusp of major lateral teeth of radula is bidentate. Color of tegmentum is chestnut with blue spots........ Tonicia disjuncta (Frembly, 1827)

2(1) Girdle does not connect between valves. Cusp of major lateral teeth of radula is unidentate. Tegmentum with no blue spots.

3(4) Color of sutural laminae is brown. Tegmentum is smooth without longitudinal grooves on both sides of the jugum.….....…… Tonicia lebruni Rochebrune, 1884

4(3) Color of sutural laminae is white. Tegmentum is granulated or rare smooth with grooves near the jugal area.

5(6) The head valve, lateral, and postmucronal areas have radiating ribs. The ratio of the width of valve V to its length is 3.4–3.9. The ratio of the length of the postmucronal area to the length of the antemucronal area of the tail valve is 2.5–3.0... Tonicia swainsoni (Sowerby, 1832)

6(5) Radiating ribs on the head valve, lateral, and postmucronal areas are absent. The ratio of the width of valve V to its length is less than 3.0. The ratio of the length of the postmucronal area to the length of the antemucronal area of the tail valve is 1.9 or less.

7(8) The tegmentum is smooth without granules or pustules except several narrow, short, weak longitudinal grooves on both sides of the jugum …........…….............................. ................................. Tonicia calbucensis southern ecotype

8(7) The tegmentum has grooves, granules or pustules.

9(10) All valves or part of them are colored with numerous undulated concentric lines. The ratio of the length of the postmucronal area to the length of the antemucronal area of the tail valve is 1.9. Both sides of the jugum have few short narrow, bent grooves …......................................... ...................................... Tonicia fremblyana Kaas, 1957

10(9) The color of the valves is variable. The ratio of the length of the postmucronal area to the length of the antemucronal area of the tail valve is 1.8 or less. Both sides of the jugum have few or numerous long grooves.

11(12) Both sides of the jugum have 10 or more narrow longitudinal grooves…… Tonicia chilensis northern ecotype

12(11) Both sides of the jugum have 1-5 narrow, longitudinal grooves.

13(14) The ratio of the width of valve V to its length is 1.8–2.1. Tegmentum is very minutely granulose. Perinotum has numerous short bristles .....................................……..… ................................... Tonicia chilensis southern ecotype

14(13) The ratio of the width of valve V to its length is 2.3–2.8. Tegmentum has granules of medium size. Perinotum does not have bristles ..................................................... .............................. Tonicia calbucensis northern ecotype