Choricotyle sp. 1

Mendoza-Franco, Edgar F., Tun, Mariela del Carmen Rosado, Anchevida, Allan de Jesus Duarte & Rodriguez, Rodolfo E. del Rio, 2018, Morphological and molecular (28 S rRNA) data of monogeneans (Platyhelminthes) infecting the gill lamellae of marine fishes in the Campeche Bank, southwest Gulf of Mexico, ZooKeys 783, pp. 125-161 : 125

Choricotyle sp. 1 Figure 7A, B, F

Present study.

Haemulon plumieri (new host)

Locality/prevalence, abundance and intensity of infection.

San Francisco: 53 fish (mean TL 28.8 cm; range 22-34) infected of 90 examined (58.9 %); abundance, 1; intensity of infection, 1-4 worms. Seyba Playa: 59 fish (TL 28.9; 21.5-31.3) infected of 90 examined (65.5%); abundance, 3; intensity of infection, 1-6. Champoton: 53 fish (TL 28.8; 19.3-33.3) infected of 90 examined (58.9%); abundance, 3; intensity of infection, 2-7.

Measurements (based on nine specimens).

Body, 2,260 (1,580-3050; 8) long. Maximum width 514 (400-635; 5) at germarium level. Two oral suckers 56 (45-60; 8) long by 40-44 width. Opisthaptor with eight narrow peduncles. Clamps 214 (150-362; 24) long, 191 (130-325; 20) wide, with 6-7 concentric arcs of small skeletal rods in dorsal fields of clamp and an apparent sucker on internal quadrant on clamp (see Ca and Sc in Figure 7A). Terminal lappet on slight posterior protrusion between third and fourth clamp with one pair (at least) of hooks, each 30 (27-33; 3) long, base 7 (6-7; 3) wide, with short filament (see Fi in Figure 7F) connecting shank and base. Genital atrium 39 (30-45; 6) long, 37 (30-45; 8) wide, armed with ten spines in a single concentric row (see Figure 7B). Number of testes 12, each subspherical, 101 (80-145; 4) long, 109 (80-140; 4) wide. Vas deferens, Ootype and Mehli´s gland, seminal receptacle, genito-intestinal canal and oviduct not observed. Eggs, 125-150 long, 65-70 wide, each with two polar filaments.

Comments.

Placement of present specimens in Choricotyle is based on examination of original descriptions of other species allocated or currently assigned to the genus in Fujii (1944), Hargis (1955b), Kritsky and Bilqees (1973), Oliva (1987), Lamothe-Argumedo et al. (1998), Oliva et al. (2009), and Cohen et al. (2011). While the eight specimens of Choricotyle sp. 1 were unsatisfactory to clarify details of internal organs for species identification, they appear to represent an undescribed species based on the general morphology of the haptor and genital atrium. Choricotyle sp. 1 resembles C. anisotremi Oliva, 1987 on Anisotremus scapularis (Tschudi, 1846) from Chile; C. aspinorcha Hargis, 1955b on Orthopristis chrysopterus [now Orthopristis chrysoptera Linnaeus, (1766)] from Beaufort, North Carolina, USA; and C. hysteroncha (Fujii, 1944) Sproston, 1946 on Bathystoma striatum [now Haemulon striatum Linnaeus, (1758)] (type host), Brachygenys chrysargyreus [now Haemulon chrysargyreus ( Günther, 1859)] and Haemulon flavolineatum (Desmarest, 1823) from Tortugas, Florida USA. All these monogeneans share the following features: presence of a sucker on internal quadrant on clamp (present in Choricotyle sp. 1 and C. anisotremi ), relatively similar morphometry of clamps (i.e., 150-362 long × 130-325 vs. 152-219 in diameter in C. aspinorcha ), number of spines of the genital atrium (10 spines in Choricotyle sp. 1 and C. aspinorcha ), and a lappet with one pair of hooks, each with 27-33 long (one pair, each with 28 long in C. hysteroncha ). Choricotyle sp. 1 differs from these three latter monogenean species by number of testes (12 vs. 90 in C. anisotremi , 42-88 in C. aspinorcha , and 6-7 in C. hysteroncha ).

The finding of Choricotyle sp. 1 constitutes the second record (the first being that of Choricotyle leonilavazquezae Lamothe-Argumedo, Aranda-Cruz & Pérez-Ponce de León, 1998, that occurs on the Pacific coast of Mexico) of a species of Choricotyle in Mexico and the first record on H. plumieri . In the present study, three species of Choricotyle (i.e., Choricotyle sp. 1, Choricotyle sp. 2 and Choricotyle sp. 3) were identified on this latter host species (see below) based on morphological features of the genital atrium, clamps and hooks on terminal lappets (when present), if they actually represent different species since variability in these diclidophorids might exhibit intraspecific differences in the shape or size of these structures above mentioned (see Yang et al. 2007).

Molecular data.

The present study also provided the first molecular data on species of Choricotyle in Mexico; both sequences of Choricotyle sp. 1 included into the present analyses revealed that this species forms a sister lineage to that containing C. anisotremi (see Figure 6) which occurs on A. scapularis ( Pomadasyidae ) from Chile ( Oliva 1987).

Specimens deposited.

Nine reference specimens, CNHE (10618).

Other two slides, each containing a haptor of a specimen of Choricotyle sp. 1 used to amplify its DNA are deposited in the CNHE (10624 and 10625).

Representative DNA sequence.

GenBank accession number MG586865, MG586866.