Table 2 Phenotypic characteristics facilitating the classification and differentiation of the lymnaeid snails species present in the fascioliasis hyperendemic area in Cajamarca

Shell:

- maximum length

12.00 mm

10.36 mm

8.06 mm

- whorls

stepped

convex

regularly convex

- columella

folded

slightly curved and unfolded

straight

Living specimens:

- Tentacles

wider and with a wide base

*

elongate, slender and with a narrow base

- Eyes

small

*

big and larger

- Colour

mantle roof shows larger unpigmented whitish spots giving a pale appearance to the shell of living specimens by transparency

*

mantle roof from dark brown to blackish throughout, with unpigmented white-greyish round spots, giving a dark appearance to the shell by transparency

Anatomy:

- Praeputium/penis sheath length ratio

2.50-5.90 mm (mean 3.44 mm)

1.10-3.90 mm (mean 2.12-2.70 mm)

1.20-2.23 mm (mean 1.60 mm)

- Radula

first bilateral teeth tricuspid

first bilateral teeth bicuspid but occasionally tricuspid or rarely quadricuspid

first bilateral teeth mostly bicuspid

Egg clusters:

- Cluster shape

rounded to oval shape even when containing more eggs

rounded to oval when containing few eggs and lengthening with slightly curved trend when including more eggs

kidney- to banana-like, the more curved, elongated and narrow the more numerous are the eggs inside

- Egg number/cluster

usually 2-15

around 4-16

around 6-14

Ecology:

- amphibious/terrestr

++

++

+++ (terrestrial trend)

- anthropophyly

+++

+

++

Transmission Capacity:

- to humans

+++

+

-

- to animals

+++

+++

-