Comparative Parasitology 67(1) 2000 - Peru State College

1987, and from these only a sample of parasites
that were seen grossly was collected. Twelve additional
eastern indigo snakes were quantitatively
examined for parasites between 1992 and
1999. Snakes were collected as roadkills in the
following counties in Florida: Alachua (n =1),
Brevard (n = 4), Charlotte (n = 1), Indian River
(n = 1), Levy (n = 1), Monroe (n = 2), Okaloosa
(n = 1), and Osceola (n — 1). Most snakes
were frozen until necropsy, when they were examined
following the methods of Kinsella and
Forrester (1972). Because of small sample size
and the lack of comparable sampling techniques,
no statistical analysis was attempted. All indigo
snake specimens were deposited in the Florida
Museum of Natural History, Gainesville, Florida.
Snakes were collected under state and federal
collection and salvage permits. Cestodes
and trematodes were preserved in Roudabush's
AFA and nematodes in 70% ethanol with glycerin.
Cestodes and trematodes were stained with
either Hams' hematoxylin or Semichon's acetocarmine
and mounted in neutral Canada balsam.
Nematodes were cleared and mounted in
lactophenol. Tissues for histological examination
were fixed in 10% neutral buffered formalin,
routinely processed, paraffin-embedded, sectioned
at 5 (Am, and stained with hematoxylin
and eosin. Terminology used follows Bush et al.
(1997). Voucher specimens of helminths were
deposited in the United States National Parasite
Collection, Beltsville, Maryland (accession
numbers 88619-88632, 88642-88643), and
ticks were deposited in the National Tick Collection,
Statesboro, Georgia, U.S.A. (accession
numbers RML122786, RML122787).
A total of 17 species of helminths (2 trematodes,
3 cestodes, 10 nematodes, 2 acanthocephalans),
1 pentastomid, and 1 tick was collected
from the 21 indigo snakes (Table 1). All helminths,
except for the 3 species of Kalicephalus,
are new host records.
From the 9 ABS snakes, the following were
identified: Kalicephalus rectiphilus, Kiricephalus
coarctatus, and cystacanths of Macracanthorhynchus
ingens. These samples were not included
in Table 1 and will not be discussed further,
but are presented here as Highlands County
records only.
Prevalences and intensities of parasites for the
12 quantitatively examined snakes are listed in
Table 1. Three species of Kalicephalus (K. inermis
coronellae, K. appendiculatus, and K. rec-
FOSTER ET AL.—RESEARCH NOTES 125
tiphilus) were collected; 6 indigo snakes had all
3 species present, and the other 6 indigo snakes
had 2 species. Schad (1962) reported that, as
adults, Kalicephalus localize themselves in the
gut without overlapping in their distribution in
the host. This seems to be true for the 3 species
of Kalicephalus in the indigo snakes we examined.
There was some overlapping in distribution
of the 3 species (Table 1), but this might
have been because of postmortem migration or
passive displacement of gut contents when the
snakes were killed.
Cystacanths of M. ingens were encysted in the
mesenteries, mainly on the serosal surface of the
small intestine. In histological sections, the cystacanths
were located predominantly within the
expanded intestinal serosa, with fewer present in
the muscular tunics, and were rarely found within
the mucosal lamina propria. The intact cystacanths
were surrounded by 1—3 layers of fibrous
connective tissue with no discernible inflammatory
response. Many of the cystacanths
were degenerated as characterized by the loss of
histological anatomic detail. In these cases, the
celomic cavities of the cystacanths were replaced
by necrotic cellular debris and fragments
of mineralized debris. This accumulation of debris
was surrounded by a rim of degenerated heterophils
and macrophages, which in turn was
surrounded by 1-3 layers of fibrous connective
tissue. Cystacanths present within the mucosal
lamina propria had been replaced entirely by
dense infiltrates of degenerated leucocytes surrounded
by multiple layers of fibrous connective
tissue. Inflammatory cells were not present outside
the fibrous capsule surrounding the degenerated
cystacanths. The presence of an inflammatory
reaction and degenerated cys.tacanths
was not reported by Goldberg et al. (1998) with
the oligacanthorhynchid cystacanths in the longnose
snakes (Rhinocheilus lecontei Baird & Girard,
1853) that they surveyed.
Elkins and Nickol (1983) reported 7 species
of Louisiana snakes that were infected with cystacanths
of M. ingens. They indicated also that
snakes may be a significant epizootiological factor
in the life cycle of M. ingens. The indigo
snake should be considered a paratenic host for
these acanthocephalans. They probably become
infected with cystacanths by several routes. Being
vertebrate generalists in their food habits,
indigo snakes in Florida prey on several species
of snakes, fishes, frogs, toads, lizards, small tur-
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