Unknowns Project 1

Date: 7 October 2012

Introduction

This was my first attempt at collecting fungi for my unknowns project. My primary goal was to collect fungi from my pig carcasses that had been decaying in the field for 6+ months. I have seen fungi on carcasses before and I thought this would be a good opportunity to figure out what was colonizing the remains after all of the insects departed.

Materials and Methods

I utilized sterile swabs in order to collect fungal samples from the skin of the pig carcasses. These swabs  were not sterile to begin with, so I wrapped each end in foil (Fig. 1), placed 5 of these in a larger foil envelope (Figs. 2, 3), and autoclaved them (Fig. 4). 

Fig. 1
Cotton swab with tip covered in foil

Fig. 2
5 cotton swabs to an envelope

Fig. 3
Sealed foil envelop containing swabs

Fig. 4
Packets placed in autoclave for sterilization

Collections: Pig 1

Pig carcasses at my field sites were in the dry-skeletal remains stage (Fig. 5). Noticeable discoloration due to mold was apparent to the naked eye (Fig. 6-9). When the hide of the carcasses was turned over, green fungal colonies were apparent (Fig. 10, 11). Each of the areas in Figs. 6-11 was swabbed with a sterile cotton swab, and then each tip was gently wrapped back in its foil covering.

Fig. 5
Pig 1 in dry-skeleton remains stage

Fig. 6
Discoloration and mold on hide on the side of the abdomen

Fig. 7
More mold and discoloration of hide. This is a view of the hind legs.

Fig. 8
Mold on the foreleg

Fig. 9
Mold on the abdomen

Fig. 10
Green fungal colonies on the underside of the hide

Fig. 11
Green fungal colonies on the underside of the hide

Pig 2

The same technique was used with pig 2, which was almost completely skeletonized (Fig. 12). There was still tissue and what looked like a black mold on the facial area (Figs. 13, 14). This pig also had green fungal colonies underneath the small amount of hide that still remained, as well as on the bones (Fig. 15). 

Fig. 12
Pig 2 almost completely skeletonized

Fig. 13
Remaining facial tissue discolored or colonized by a type of black mold

Fig. 14
Remaining facial tissue discolored or colonized by a type of black mold

Fig. 15
Green mold on bones of Pig 2

Inoculations

When I returned to the lab, I promptly inoculated 2 plates of 1/2 strength PDA (Fig. 16) with the different samples taken from each pig (i.e. each plate contained spores from only a single pig). 

Fig. 16
1/2 strength PDA used for inoculations

Conclusion
Stay tuned for the next blog to see what happens next!

All for now,

C