Use of fecal matter & superworms for Corucia

Leeway Corucia Research Center (LCRC)


Possible effects of antibiotic therapy on digestion in a Solomon Islands skink: Corucia zebrata. 2004 ( see end for an excerpt from this paper)

On this paper, I wish to comment that Corucia has not shown to prefer to engage in Coprophagy. Indeed, neonates gain beneficial bacteria by consuming the mother's placenta -not by consuming fecal matter. This has been documented many times by different researchers. Schnirel, (2004), DuPont, (2005), Jones, (2007). Also, Corucia by all accounts, are a strict herbivorous species -Iverson (1980), `R. Jorndal, (1997), Mackie,et al. (2004). This is shown by the colic partitioning and transverse folds/valves in the colon for the slow passage rate of cellulose food. Large Mealworms are not a food source suggested for Corucia in that they have a hard cuticle which is hard to digest -especially in a slow digestional tract reptile such as Corucia. This could easily lead to impaction. Also, these meal worms have a low calcium/phosphorus ratio. There is also much debate on the fat content as well. To give a mealworm only diet for a very long period with this species was not the best course. Even if Corucia were to practice coprophagy, Why were coated soft vegetables not used? This would have facilitated digestion in a weakened animal.

Sincerely,
Brian / Sherri
LCRC

excerpt from: Possible effects of antibiotic therapy on digestion in a Solomon Island skink, Corucia zebrata. 2004. Tara Wadding, Stephanie Louise Mann, Margaret Davies, and Roger Meek.

The paper mentions a sub adult Corucia in a small colony housed in an enclosure 7.5 x 10 meters horizontally and 3.3 meters vertically at Huddersfield Technical college that showed signs of a skin infection. The Corucia was taken to a vet who prescribed Baytril ) dosage = 1 ml per 5 kg body weight) repeated at 5 and 10 day intervals. The Corucia was then given a liquid recovery diet orally using a syringe and subsequently appeared to have recovered. "Since it began feeding well on it's normal diet of a mixture of fruits and vegetables and occasional giant mealworms ; we presume it was also feeding on the vegetation growing in the enclosure which was normal practice for the colony. However, some weeks later, it was noticed that there was a gradual decline in condition, "....(it's no wonder, from the hard to digest cuticle of a superworm) ..."despite a continuing good appetite." ...(probably had an impaction)... "We considered the possibility that the antibiotic treatments may have had an adverse effect on the lizard's microbe and nematode population and hence we decided to induce 'artifical coprophagy' in an attempt to 'reintroduce' an intestinal fauna (Iverson, 1979; Troyer, 1982). This was achieved by offering Several Giant mealworms smeared with the faeces of it's cage mates"... (Why not vegetables??),..." a procedure that was repeated twice within the following week"... (poor thing, with nothing else given, I guess after awhile even fecal matter covered worms would be eaten)..." In a relatively short time, period, 2 weeks or so"...(imagine, being a Corucia eating nothing but crap coated hard shelled worms for 2 weeks!)...." the lizard began to regain condition and approximately at a 2 month period was back to normal weight. We suspect that this incidence with C. zebrata was a case of maldigestion through the application of the antibiotic, although our evidence for this was circumstantial."... (yes, they were grasping straws - not operating in a systematic scientific fashion)..." Indeed, there were several curious aspects concerning the incident. For instance, why we should have had to induce 'artificial coprophagy' rather than the animal performing this naturally"... (because Corucia do not eat their own waste naturally!)...." is not immediately obvious "

The paper goes on about how certain antibiotics eliminating intestinal faunas. They mention the Tewksbury Institute of Herpetology "which has an ongoing research programme on C. zebrata, avoids the regular use of anti-parasitic drugs such as Metronidazol unless potentially harmful protozoa have been identified as present (Richard Ogust, pers. communication)".

I have just become a member of this forum and was astonished to see this comment. The reason I am astonished is that I communicated with one of the authors (Brian?) some months ago by e-mail and addressed the critical comments and misrepresentations he made then, which are unfortunately repeated here. As one of the authors of the paper in question, and since he again insists on misrepresenting the papers content, I am obliged to reply (again!). The reason we submitted the m.s. was simply to draw attention to the potential problems of certain antibiotics which may be more relevant to herbivorous reptiles that carnivorous forms.

The major problem with the authors views is that they have again not read the paper carefully, which was pointed in our initial correspondence. In addition to mis-representing the papers content they make many unfounded assumptions on Corucia behaviour that do not appear to have been researched, particularly in wild populations

We did not say at any point in the paper that ``Corucia prefer to engage in Coprophagy`` or that mealworms were a significant component of our colonies diet. What we did say was that mealworms were occasionally offered as food but that the diet was fruits and vegetables. We also drew attention to fact that the animals also independantly foraged for themselves on naturally growing plants in a large 7.5m x 10m by 3.5m high naturalistic enclosure - which was glass covered incidentally. Clearly mealworms were only a tiny fraction of the diet. It is therefore very difficult indeed to understand why the author(s) make comments such as ``To give a mealworm only diet for a very long period with this species was not the best course`` or "poor thing, with nothing else given, I guess after awhile even fecal matter covered worms would be eaten". The authors also repeat this kind of nonsense in regard to the after treatment diet of the subject lizard by saying ``imagine, being a Corucia eating nothing but crap coated hard shelled worms for 2 weeks!``. We have nowhere said this was the food for the following two weeks.

Considering the misrepresentations of our paper it really is outrageous that the authors should suggest that we were ``grasping straws - not operating in a systematic scientific fashion``!! The paper was not, and never at any time claimed to be based on a scientific experiment. It was simply a one-off observation and described as such. We employed coprophagy as a tool to induce the animal to ingest potential beneficial bacteria and do not know for certain if the method worked, only that the animal recovered – it could have recovered for some other reason! Additionally, mealworms were used simply because it was the only food the animals would take from the hand of the technicians (remember that these lizards were in a large enclosure and not familiar with their keepers in the way that animals kept in smaller enclosures in private residences would be) and hence we could be certain that the faeces were consumed. We assumed in the paper that coprophagy is a possibility in wild populations (but did not claim dogmatically that it is) as it has been indicated in some other herbivorous reptiles. However, determining this scientifically is difficult, as the animals would have to be monitored for 24 hours every day over long periods (although the authors appear to claim that they have done this field work, eg `` Corucia do not eat their own waste naturally``. In our paper we frequently use the terms `possible` `considered the possibility` `we suspect`- nowhere is it dogmatic.

The authors also give a presentation on the problems of mealworms – i.e. possible impaction problems, fat content etc, in the diets of Corucia which are well known of course (or suspected) at least since the 1960`s for all reptiles, although as I understand it, this has to do more with continual feeding rather than occasional. Why all this was necessary I have no idea.

In summary the authors would be better serve the herpetological community of this forum by accurately reporting the contents of journal publications and justify their own assertions on behaviour ecology of this species.

Roger Meek