Shrews are small mole-like mammals that belong to the family Soricidae, Order Eulipotyphla. Shrews are about the size of a mouse, but are closely related to hedgehogs and moles and are the only mammals (besides vampire bats) to produce venomous saliva. They feed on insects and seed, but some have specialized in hunting in the water, living in snow, climbing trees, and living underground. Some species of shrews have developed venomous saliva from the saliva glands in their body, causing bites from the shrew can cause a paralysing effect on insects, snails and small mammals, but has little effect on humans unless they are allergies to shrew bites (Ligabue-Braun et al, 2012). Below is a picture of a Southern short-tailed shrew (Blarina brevicauda).
By Unknown
Platypus (Ornithorhynchus anatinus) is a
semi-aquatic egg laying mammal that belongs to the family Ornithorhynchidae, Order Monotremata
(sometime called Monotremes). Their appearance of a duck-billed, beaver-tailed,
otter-footed mammal is unusual and baffled scientists when they first
encountered it. Both female and male platypuses have spurs on their hind legs,
but females lose their spurs during development (Whittington et al, 2010). The
spurs on the male platypus are connected to venom-producing crural glands,
forming a crural system. When attacked by another animal, the hind legs of the
platypus are driven towards each other, causing the flesh of the attacking
animal to be caught in-between the hind legs and receives venom from the spurs
by repeated jabs. Venom from a platypus is not fatal toward humans, but can
cause extreme amount to pain (Ligabue-Braun et al, 2012). Below is a picture of
a platypus.
By
Klaus - Flickr: Wild Platypus 4, CC BY-SA 2.0
Common vampire bat (Desmodus rotundus) is a small, leaf nose
bat that belong to the family Phyllostomidae,
Order Chiroptera. The Common
vampire bat is a hematophagous specialist which means that they feed of the
blood of other animals. They are one of the most social species of bats where
males defending groups of females, bringing back food for the ones that miss
out on feeding (mostly nursing mothers), and participate in social grooming. The
Common vampire bat venomous saliva contains anticoagulant properties that
prevent blood from clotting when feeding, a bat will find a host to feed (when
they are asleep) and make a small incision with it teeth (causing no pain to
the host) allowing the saliva to prevent blood from clotting and allowing the
bat to drink until it is full. The saliva is not fatal to most animals, expect
for chickens that may die of haemorrhage (Ligabue-Braun et al, 2012). Below is
a picture of a common vampire bat.
Picture taken at Sangayan Island, Paracas
National Reserve, Departamento Ica, Peru, in March 2005
In next week’s
post, we will be covering amphibians that use venom. Below are the articles
that were used in this week’s post.
References
Ligabue-Braun, R.,
Verli, H. & Carlini, C.R. 2012, "Venomous mammals: A review",
Toxicon, vol. 59, no. 7-8, pp. 680-695.
Whittington,
C.M., Papenfuss, A.T., Locke, D.P., Mardis, E.R., Wilson, R.K., Abubucker, S.,
Mitreva, M., Wong, E.S.W., Hsu, A.L., Kuchel, P.W., Belov, K. & Warren,
W.C. 2010, "Novel venom gene discovery in the platypus", Genome
Biology, vol. 11, no. 9, pp. R95-R95
