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SPECIATION AND VIABILITY OF POULTRY COCCIDIA [ Vol. XXIV, Part IV,
per cent respectively. Further, E. necatrix and E. brunetti were noted to be absent
in this survey. It may be emphasised that E. hagani has for the first time been
recorded from Indian poultry.
Observations on the viability of various coccidia are as follows : 1. Twenty-two
samples tested varying in age from 86 days to one year contained E. praecox, E.
mitis, E. acervulina, E. maxima and E. tenella, and all the species were found viable.
2. Twenty-eight samples between 1-2 years of age contained all the species
noted above, with respective percentage viability of 71, 91, 100, 71 and 86, i.e.,
9-14 per cent decline in their viability had occurred except in E. acervulina : all
the samples of which were still viable at the end of two years.
3. Twenty-nine samples between 2-3 years of age contained oocysts of E.
hagani, E. praecox, E. mitis, E. acervulina, E. maxima and E. tenella. Their per-
centage viability was of the order of 0, 54.4, 35.4, 76.5, 33 and 28 respectively. It
is apparent that a sharp decline in their viability had occurred. Almost 45, 65,
24, 67, 72 and 100 per cent samples of E. praecox, E. mitis, E. acervulina, E. maxima,
E. tenella and E. hagani respectively, were found dead between the second and third
year of preservation.
4. Twenty samples tested, between the third and fourth year of preservation,
contained all the six species of Eimeria named in para 3, and Wenyonella gallinae.
All these coccidia were dead (non-viable to susceptible birds) after three years of
preservation.
5. Rest of the 21 samples varying in age between 4 to 13 years contained E.
praecox, E. mitis, E. acervulina, E. maxima and E. tenella in varying proportions and
all of them were found dead.
It was also noted that five samples of E. tenella at the ages of 414, 463, 780 (two
samples) and 798 days respectively ; two samples of E. mitis-2 years, 7 and 9 days old
respectively ; and one sample of E. maxima-2 years and 62 days of age, recorded
abnormally long prepatent periods of 9, 7 and 8 days respectively. However,
when thus voided oocysts, after sporulation were further fed to susceptible chicks,
prepatent periods returned to the normal cycles of 7, 5 and 6 days for E. tenella,
E. mitis and E. maxima respectively. Delayed appearance of oocysts in these
experiments indicate delayed schizogony and gametogony. Probably, such a
phenomenon precedes complete decay of oocysts.
Dickinson [1948] also records a similar observation on E. tenella. His culture
was preserved at ±4°C. for 781 days. Prepatent period on first passage was a little
more than eight days which, however, on next passage returned to the usual cycle.
SUMMARY
Examination of 120 faecal samples of poultry has revealed the presence of E.
tenella, E. acervulina, E. mitis, E. maxima, E. praecox, E. hagani and Wenyonella
gallinae in them. Their order of percentage frequency of occurrence is 70, 50, 48.4,
30.8, 29.2, 2.5 and 1.7 respectively. E. hagani has for the first time been reported
from Indian poultry.
The effect of age of preservation (in 2.5 per cent potassium dichromate) on
poultry coccidia in 120 faecal samples was determined experimentally by feeding