Girardia, Ball, 1974

Catalá, Alejandro, Benítez-Álvarez, Lisandra, Diez, Yander L., Blasco, Gema & Riutort, Marta, 2024, Treasure island: DNA data reveals unknown diversity in Cuban freshwater planarians (Platyhelminthes: Tricladida), Zoologia (e 23101) 41, pp. 1-13 : 8

Diversity of Girardia in Cuba

Our results show that at least three different species of Girardia inhabit the eastern region of the island of Cuba. In the San Juan River was identified the presence of G. sinensis ( Fig. 3C ), a species for which there is a record from the western region of the archipelago ( Fig. 1 ), also based on a molecular study ( BenÍtez-Álvarez et al. 2023b). This is the first record of the species in the eastern region of Cuba. Girardia sinensis was originally described from China ( Chen et al. 2015), but later it was found to be an invasive species and it was concluded that it originated from North America and had been recently introduced worldwide by human activities ( BenÍtez-Álvarez et al. 2023a, 2023b). Up to date, Cuba is the only known record of G. sinensis in The Americas ( BenÍtez-Álvarez et al. 2023b) and Cuba is situated on the south border of the North American plate ( Iturralde-Vinent and MacPhee 1999, Iturralde-Vinent and Macphee 2023). Taking into account the high dispersal potential of this species ( BenÍtez-Álvarez et al. 2023a) and the complex geology of the American continent, at the moment it is not possible to establish whether the species is autochthonous to the island or may have arrived transported by human activities or animals.

The specimens coming from the Duaba ( Fig. 3A ) and Nima Nima rivers ( Fig. 3B ), respectively, constitute sister groups; however, the long branches separating them in the trees are indicative of a high genetic differentiation, which suggest they are two different species. These two species were sampled in localities near those of eastern Cuba where Codreanu and Balcesco (1973) described G. cubana and, therefore, one of the two molecularly identified species in the present work may correspond to G. cubana ( Figs 1 , 2 ). A morphological analysis is needed to corroborate whether any of the populations of both localities show the characteristics defined for G. cubana . However, the lack of type material or designation of a type locality in the original description of the species, together with the fact that the morphology of the copulatory apparatus of G. cubana from most of the localities was not analyzed ( Codreanu and Balcesco 1973), renders the classification of new specimens as G. cubana difficult. We suggest designating Topes de Collantes on Central Cuba as type locality for G. cubana , since the only anatomical description of the reproductive systems belongs to specimens from that locality ( Codreanu and Balcesco 1973).

Figures

Figure 1. Distribution of the previous records of planarian species in Cuba. Circles represent localities of Girardia cubana, the localities in the Central-Eastern region correspond to the original description. Diamond represents G. sinensis.

Figure 2. Sampling localities of freshwater planarians in eastern Cuba: (A) map with the distribution of the sampling localities; (B, C) rivers on not urbanized areas where B: Duaba River and C: Juan González, Nima Nima River; (D, E) rivers in urbanized areas where D: Eichhornia crassipes and Pistia stratiotes in La Fría, Cauto River and E: San Juan River note the presence of Elodea sp. in the water.

Figure 3. Different morphological types sampled from: (A) Duaba River, (B) Juan González, Nima Nima River, (C) San Juan River, (D) La Fría, Cauto River. (A–C) Girardia-like morph: (A, B) present pointed auricles; (C) triangle shaped auricles and a dotted color pattern; (D) the unknown morph without auricles. Scale bars: 2 mm.