Comparative Parasitology 67(1) 2000 - Peru State College

COMPARATIVE PARASITOLOGY, 67(1), JANUARY 2000
Cenote (15 April 1998), 1/1, 20; Cichlasoma octofasciatum
(Regan, 1903), Cedros River (19
May 1998), 4/4, 4 (1-7); Cichlasoma trimaculatum
(Giinther, 1869), Champerico River (16
December 1995), 3/3, 34 (14-37); C. urophthalmus,
El Yucateco Lagoon (30 January 1998), 7/
8, 65 (2-284); Cenote Azul (2 March 1998), I/
3; 4, Mahahual (2 March 1998), 3/3, 16 (4-16);
Dzonot Cervera Cenote (15 April 1998), 1/3, 1;
Rancho Don Milo (8 May 1998), 1/3, 12; La
Pera Lagoon (15 June 1998), 1/8, 50; Petentuche
Cenote (10 October 1997), 1/1, 52; P. splendida,
Dzaptun Cenote (21 August 1996), 1/1, 18; Silvituc
Lagoon (15 July 1997), 1/1, 7; Valle Hermoso
Lagoon (2 March 1998), 1/1, 15; Palizada
River (15 June 1998), 1/2, 12; Santa Anita Lagoon
(24 April 1998), 1/1.
SPECIMENS DEPOSITED: Voucher specimens
from C. aureum and C. friedrichstahli in
USNPC (Nos. 88943 and 88945); from C. tri
maculatum in CNHE (No. 3136), USNPC (No.
88944), BMNH (No. 1999.7.13.25), and CHCM
(Nos. 224 and 225); from P. splendida in CNHE
(Nos. 3135 and 3136), IPCAS (No. M-343),
USNPC (No. 87303), and CHCM (No. 220).
REMARKS: The morphology and measurements
of the specimens found in the different
hosts correspond well to the description of S.
mexicanum from C. urophthalmus by Kritsky et
al. (1994). Cichlasoma aureum, C. trimaculatum,
and P. splendida represent new host records.
The finding of S. mexicanum in Guatemala
is the first record of this parasite in Central
America. The present data, together with those
of Mendoza-Franco et al. (1999), who reported
S. mexicanum from C. friedrichstahli, C. octofasciatum,
and C. synspilum, demonstrate a wide
host specificity of 5. mexicanum.
Sciadicleithrum splendidae Kritsky,
Vidal-Martmez, and Rodriguez-Canul, 1994
(Figs. 1-11)
MEASUREMENTS: Measurements of 41 specimens
studied from different hosts and localities
are given in Table 2.
HOSTS, LOCALITIES, SAMPLING DATES, AND PA-
RAMETERS OF INFECTION: C. friedrichstahli,
Dzaptun Cenote (1 August 1997), 1/1, 9; Mahahual
(2 March 1998), 2/2, 9 (7-11); Cedros River
(19 May 1998), 8/15, 10 (1-18); C. managuense,
Santa Gertrudis (17 March 1998), 1/1, 4.
SPECIMENS DEPOSITED: Voucher specimens
from C. friedrichstahli in CNHE (Nos. 3720 and
Copyright © 2011, The Helminthological Society of Washington
3721), CHCM (No. 218), USNPC (Nos. 88948
and 88949), and BMNH (No. 1999.7.13.26).
REMARKS: Both species of Cichlasoma studied
are new hosts of S. splendidae. Specimens
obtained from C. friedrichstahli closely resemble
in their morphology those of S. splendidae
from P. splendida previously described by Kritsky
et al. (1994). All possess hamuli relatively
similar in size and shape, the base of the copulatory
organ with bilobed proximal branch, and
a vagina comprising a sclerotized tube looping
anteriorly on the dextromedial half of the trunk.
However, there are slight differences between
the present material and that of S. splendidae in
the number of coils of the male copulatory organ
(1.5 rings in the specimens studied versus more
than 2 in S. splendidae) and the size of the accessory
piece, 38 (30—45) in worms from C.
friedrichstahli and 22 in specimens from the
type host. Similarly to S. bravohollisae, the differences
in the measurements of sclerotized and
soft body parts of specimens from C. friedrichstahli
might be related to the size of the worms
and the method of fixation (see Fig. 6). A similar
phenomenon has previously been observed
among individual specimens of Sciadicleithrum
umbilicum Kritsky, Thatcher, and Boeger, 1989,
from South America (Kritsky et al., 1989).
The original description of S. splendidae was
based on only 2 specimens (Kritsky et al., 1994).
The additional material from this study evidences
that the shape and number of coils of the male
copulatory organ vary among specimens from
the same hosts (Figs. 2-4) and that this species
possesses a seminal vesicle (see Fig. 1) that
lacks a thickened wall, as is present in congeneric
species of Sciadicleithrum from Yucatan
(Kritsky et al., 1994; Mendoza-Franco et al.,
1997). As for S. bravohollisae, S. splendidae occurs
in members of 2 genera of cichlid fishes,
Cichlasoma and Petenia.
Discussion
Species of Sciadicleithrum were first reported
from cichlids from South America (Kritsky et
al., 1989) and subsequently from cichlid fishes
from southeastern Mexico (Kritsky et al., 1994;
Mendoza-Franco et al., 1997, 1999). The present
study confirmed previous observations by the
latter authors that the fauna of monogeneans assigned
to Sciadicleithrum from the Yucatan Peninsula
of Mexico and neighboring areas is depauperate
in the number of species.