Archigetes sp. 1

Toma, Scholz, s, P, Gerardo & Leon, erez-Ponce de, 2021, Caryophyllidean tapeworms (Cestoda), Nearctic parasites of fish in Mexico, including description of a new species of Isoglaridacris and the first report of Khawia japonensis, an invasive parasite of common carp (Cyprinus carpio), International Journal for Parasitology: Parasites and Wildlife 15, pp. 70-78 : 71-72

1. Archigetes sp. 1 Fig. 1A, C, F

Material studied: One specimen from yellow shiner, Notropis calientis Jordan and Snyder ( Cypriniformes : Leuciscidae ), Lago de Zacapu, Michoac´an, collected by Berenit Mendoza-Garfias in November 2008 ( CNHE 6800).

Host: Notropis calientis .

Distribution: Mexico (Michoac´an).

Remarks

The single specimen found is strongly flattened ( Fig. 1A ), which affected its measurements and made its anatomy difficult to observe, partly also due to extensive vitelline follicles which obscure other structures in the body. The specimen possesses characteristics typical of

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Archigetes Leuckart, 1878 , namely small size of the body (length 2.45 mm, maximum width 910 μm near the middle of the body, length: width ratio 1: 0.37; Fig. 1A ), bothrioloculodiscate scolex (for terminology of scoleces of caryophyllidean tapeworms – see Figs. 5.1–5.21 in Mackiewicz, 1994), which is 350 μm long and 650 μm wide ( Fig. 1C ), a defined neck is absent, an external seminal vesicle is well-developed, 79 μm long and 35 μm wide ( Fig. 1F ), a single gonopore, and uterine loops anterior to the cirrus-sac, which is 165 μm long and 150 μm wide ( Fig. 1F ). The testicular field spans anteriorly almost from the level of the anterior-most vitelline follicles to the level of the anterior-most loops of the uterus, but does not reach the level of the cirrus-sac ( Fig. 1F ). Anterior-most vitelline follicles are situated 520 μm posterior to the anterior extremity, i.e., 21% of total body length, 26 μm anterior to anterior-most testes, which start 546 μm posterior to the anterior extremity (22% of total body length). Vitelline follicles are extensive, surround the testes and are present also lateral or laterodorsal to the ovarian arms, thus connecting the preovarian field of follicles with postovarian vitelline follicles ( Fig. 1F ). Intrauterine eggs are 51–55 μm long and 30–35 μm wide.

Figures

Fig. 1. Archigetes sp. 1 from Notropis caliensis, Michoac´an (CNHE 6800) (A, C, F); Archigetes (?) sp. 2 from Notropis nazas, Durango (CNHE 6797) (B, E); Archigetes sp. 3 from Chirostoma sp., Michoac´an (CNHE 6801) (D). A, B – total view, dorsally; C, E – anterior part with scolex; note different position of anterior-most testes and vitelline follicles between C and E; D – total view, ventrally; F – ovarian and uterine region, dorsally. Abbreviations: cs – cirrus-sac; eb – excretory bladder; eg – eggs; esv – external seminal vesicle; lo – loculi; ov – ovary; sr – seminal receptacle; te – testes; vf – vitelline follicles.