To search on the WoRMS database, we selected the distribution tab and chose “Chile (Nation)” under geounit. Then, we limited taxa to “Dugesiidae Ball, 1974” and asked to include all records, unchecking “extant only” and “marine taxa”. To search within the TTD (Tyler et al. 2006–2020), we selected “Chile” under the geographic distribution search and generated a list to find freshwater species. We complemented the information following the original publications available.

The map was generated using QGIS Hannover version 3.16 incorporating the coordinates as delimited text layers (.csv) for each species. Then, we edited the images on Adobe Photoshop 2021 to add location numbers. Planarian drawings and copulatory apparatus sketches were recreated using Adobe Illustrator and Photoshop 2021.

Synonyms. Planaria ambigua Böhmig, 1902; Curtisia ambigua Marcus 1954.

Distribution. Southern Chile (Magallanes Region).

The original description of the species was made by Böhmig (1902). The specimens were collected in 1893 during the Hamburg Magalhaensian collecting trip to Patagonia, from a large lake in Punta Arenas (Fig. 1, spot 22), at approximately 300 m above sea level (masl). No details are provided regarding the lake. The dorsal surface of the specimen is of deep brown, blackish or dirty olive-green color. A whitish or yellowish color appears on the side margins, the midline and on the ventral side, on which brownish spots are occasionally noticeable. The head tip is blunt; the posterior end is bluntly pointed (Fig. 2A, Table 2).

The largest organism collected was about 7 mm long and 3 mm wide after fixation, but its copulatory organs were immature and the definitive configuration could not be concluded, thus the specimen was named Planaria ambigua. The mouth lies at the beginning of the posterior third and the genital gonopore is about 0.5 mm away from it. The ovaries are found in the anterior region and the testes lie dorsal between the third and fourth branches. Marcus (1946, 1954) proposed that this species belongs to the genus Cura Strand, 1942, because the testes do not extend beyond the base of the pharynx. In concordance, because no mature reproductive organ was available for analysis, he did not include C. ambigua in his list of turbellaria from Chile (Marcus 1954). Later, Ball (1974) considered that the species was inadequately described and suggested it probably belongs to the genus Dugesia. Finally, after examining several specimens collected in the area, Kawakatsu et al. (1984a) commented that Pl. ambigua is very similar to R. patagonicus, the predominant triclad in southern Patagonia. This triclad remains as species inquirenda.

Synonyms. Planaria similis Böhmig, 1902.

Distribution. Central Chile (Valparaíso Region).

Very little information has been published on Dugesia similis. Many specimens were collected in 1893 in Salto brook (Fig. 1, spot 9), near Valparaíso, and described by Böhmig (1902). The climate in this region is Mediterranean, characterized by dry warm summers and wet mild winters. Most specimens showed signs of asexual reproduction by fission. Accordingly, size varied between 1.5–7.0 mm in length and 1.5–2.5 mm in width, and the number of secondary intestinal posterior branches was very variable, probably because body fission takes place at different distances from the mouth opening. When possible, Böhmig represented genital organs with special attention to the glands connected with them, which play a main role in identifying individual species. However, specimens of Planaria similis had no mature reproductive organs and therefore could not be truly identified.

The author commented that the animals are very similar in body conformation to the North American Planaria maculata Leidy, 1847 (a synonym of Girardia tigrina Girard, 1850): a slender anterior, acute-triangular head shape and pointed rear end (Fig. 2B, Table 2). The dorsal side was colored dark brown, almost blackish, caused by isolated or confluent pigment spots covering the pale-yellow background. The ventral side was either evenly colored light gray or blackish spotted. The auricles were clearly recognizable in all individuals, conical, whitish and are very sharply defined from the body.

de Beauchamp (1939) assigned the species to Dugesia. However, because no reproductive organ was available for analysis, Marcus did not include this species in his list of turbellaria from Chile (Marcus 1946, 1954). He also highlighted that D. similis differs in coloration from G. chilla, a species collected in the same area (Hyman 1959). D. similis remains as species inquirenda.

Synonyms. none.

Distribution. Central Chile (Metropolitana and Valparaíso Regions).

The discovery of this species dates back to 1986. The authors’ particular interest was to find G. festae in the locations previously described by Hyman (1959). Instead, Girardia canai was collected under stones in backwater areas of the Mapocho River near the province of Talagante and at the mouth of the Reñaca Estuary, Valparaíso (Fig. 1, spots 6 and 11) (Curino and Cazzaniga 1993). The Mapocho flows from the Andes through Santiago and is the principal river of the capital. The authors named the species under the genus Girardia, due to its morphology and the characteristics of its reproductive system, and “canai’’ which means “friend” in Mapudungun, the native language of the Mapuche ethnic group, in honor of the friendship provided by Patricio Sánchez, a Professor at Universidad Católica at the time, who helped in the collection of the specimens. Fixed specimens measured 9–10 mm long and 2–4 mm wide. The external morphology showed the typical triangular shape of the genus Girardia, with visible rounded auricles and a pair of eye cups. The dorsal pigmentation was mainly light brown, with dark brown spots that might form a longitudinal mid stripe. The number of spots and the presence of the stripe were very variable (Fig. 2C, Table 2). The pharynx was pigmented.

The authors examined sixteen mature specimens and thus provided a very detailed description of the reproductive apparatus (Fig. 3A). Testes run on both sides of the ventral nerve cords, extending along the length of the body. The extrapenial seminal vesicles or “false seminal vesicles” (se) are well developed, forming two wide tubes filled with sperm that originate from the anterior half of the pharynx. The course of the sperm ducts is asymmetrical and variable within the specimens, and the authors describe three types of patterns for their course, but in general they run into the penis bulb without forming intrabulbar enlargements. The penis papilla (pp) of G. canai is notably long. This species can be distinguishable from G. chilla (Fig. 3B), which has an enormous cavity in the penial bulb. Ovoid ovaries are located directly posterior to brain branches. The ovovitelline ducts (od) open separately at a minimum distance between them and run dorsally until before the gonopore (go) where they curve and run towards a mid-sagittal plane and then curve again and open in the bursal canal (bc). Furthermore, this species presents two muscle layers in the angled bursal canal, characteristic of the genus Girardia.

Synonyms. Dugesia chilla Marcus, 1954; Dugesia veneranda Martins, 1970.

Distribution. Central and South Chile (Valparaíso, Los Lagos and Magallanes Regions), Brazil, Argentina.

G. chilla has some peculiar characteristics, including a stubby cone or ball-shaped penis papilla and dorsal or dorsoventral testes. The first description of this species was made by Marcus (1954) under the name of Dugesia chilla, after the Lund University expedition in 1948–1949, when forty-nine specimens were collected and analyzed. The author provided a general description based on the external morphology and reproductive system of specimens collected from three localities in southern Chile: Llanquihue, Chiloé Island and Punta Arenas (Fig. 1, spots 15, 16 and 23). Later, Hyman (1959) complemented the description, and provided Sánchez’ notes on the species collected from three places in Valparaíso Region, central Chile (Fig. 1, spots 2, 3 and 10). More recently, Sluys (1996) confirmed that Dugesia veneranda, originally described from Brazil by Martins (1970), is a junior synonym of G. chilla, as suggested earlier (Ball 1974; Kenk 1974).

The specimens are slender, measuring approximately 9–25 mm long and 2–4.5 mm wide. The head is large, narrow, and pointy with protruding flexible auricles. Dorsal pigmentation is uniformly dark, dense, with grayish, hassle and black hues (Fig. 2D, Table 2). The ventral side is much paler with light bluish gray color. The pharynx is 4 mm long with gray pigment, typical of the genus Girardia. Eye size varies among specimens, suggesting that the worms might be at different regeneration stages after reproducing by fission. In concordance, Hyman (1959) mentioned that when the species is in an asexual state, it undergoes fission behind the pharynx and, in its sexual state during spring through summer, it lays cocoons with peduncles on the lower sides of the stones from which several juveniles hatch three to five weeks later.

Marcus’s specimens from Pichi Pilluco Estuary, Llanquihue, were sexually mature, but the samples were contracted, and reconstruction of its copulatory apparatus was criticized by Hyman (1959). She provided a detailed description of relaxed samples (Fig. 3B), supplementing the histological description that coincides with several aspects, including the characteristic globular penis (pp) and ball-shaped copulatory bursa (cb). Sluys et al. (2005) redescribed the species by comparing specimens from Argentina and Chile. The bursal canal (bc) is characteristic as it frequently shows constrictions (Marcus 1954; Sluys et al. 2005), which were not seen in samples from Valparaíso or São Paulo (Hyman 1959; Sluys 1996). This difference was attributed to the age of the animals (Sluys 1996). The bursal canal receives the opening of the unified ovovitelline ducts (od) at the posterior section and the openings of shell glands (sg) immediately ventral to them.

The species seems to be distributed across South America. G. chilla has also been found in two locations in Southern Argentina: Moreno Lake at 765 masl and Ñireco River (Sluys et al. 2005). Thus, the range of G. chilla extends from 32°S to 53°S. The species coexists with G. festae in Huallilemu Estuary and El Tigre Brook. However, G. chilla is less suitable for culturing in the laboratory.

Synonyms. Planaria festae Borelli, 1898; Planaria dimorpha Böhmig, 1902; Planaria polyorchis Fuhrmann, 1914; Euplanaria aurita de Beauchamp, 1939; Dugesia titicana Hyman, 1939; Dugesia polyorchis Kenk, 1941; Dugesia dimorpha Marcus, 1954; Dugesia festai Marcus, 1954; Dugesia (Girardia) sanchezi Hyman, 1959; Dugesia (Girardia) polyorchis Ball, 1974; Girardia festai Sluys, 1992.

Distribution: Central and Southern Chile (Valparaíso, Metropolitana, Biobío and Los Ríos Regions), Argentina, Peru, Ecuador, Bolivia, Venezuela, Colombia, Curaçao, Brazil, Uruguay, Paraguay.

Girardia festae is one of the planarians present in Chile with the largest distribution and several synonyms. It has been found in springs, streams and lakes at altitudes up to 4800 masl. Its Latin American distribution has been summarized elsewhere (Kawakatsu and Mitchell 1984; Sluys 1992; Brusa et al. 2012). The first description dates back to the 19^th century by Borelli (1898), where he described specimens found in Ecuador under the name Planaria festae. Four years later, Böhmig (1902) described Planaria dimorpha based on specimens found in Quilpué and Valdivia, Chile (Fig. 1, spots 8 and 13). Marcus (1954) briefly mentioned that Pl. dimorpha and Pl. festae should be included in the Dugesia genus, thus renaming them Dugesia dimorpha and Dugesia festai. Then, Hyman (1959) published a description as a new species under the name of Dugesia sanchezi in honor of Patricio Sánchez, who found the specimens in different locations in the Metropolitana and Valparaíso Regions (Fig. 1, spots 3–7, 10 and 11). Marcus (1960) described the species from Curaçao and Sluys (1992) offered a redescription under the name of G. festae comparing with the information provided by Böhmig (1902) and Hyman (1959), and proposing that G. dimorpha is a junior synonym of G. festae. Benazzi (1978, 1981) published articles in which he described the reproductive biology of G. festae from specimens obtained near Concepción, Chile (Fig. 1, spot 12). Then, Moretto (1996) redescribed the planarian collected in the Mapocho River (Fig. 1, spot 11) and reared in his laboratory. Finally, Sluys et al. (2005) redescribed specimens collected from Brazil, Paraguay and Argentina under the genus Girardia, remaining as Girardia festae.

The species reaches dimensions of 10–20 mm long and 1.5–4 mm wide. It has a triangular head with pointed auricles, typical of the genus Girardia. The body has the same width up to the rear third of the body, then narrows into a pointy posterior end. The dorsal pigmentation is variable, generally brown that varies towards grayish or yellow tones, with or without a clear longitudinal midline, plus a pattern of granular pigmentation that can be uniform throughout the body or distributed in the lateral regions (Fig. 2E, Table 2). While on the ventral side it presents a uniform gray-yellowish pigmentation. G. festae cohabits with G. chilla at Huallilemu Estuary and El Tigre Brook, Valparaíso.

The reproductive system of G. festae (Fig. 3C) consists of two ovaries in an anterior position between the second and third intestinal diverticula. Ovovitelline ducts run beyond the gonopore (go) and turn dorsally to connect with the bursal canal (bc), while numerous testes are located ventral to the ovaries and extend posteriorly through the lateral regions. In some specimens, testes extend dorsally, occupying the dorsoventral space. The penis papilla (pp) is characteristic as it has two lobes and does not have much muscle. The sperm ducts join to the penis bulb latero-dorsally. Regarding the reproductive biology of G. festae, the species can reproduce both sexually and asexually by fission. These are diploid organisms with eight pairs of chromosomes (Benazzi 1981; Puccinelli and Deri 1991). Egg capsules are round with a dark-brown pigmentation and the peduncle is amber in color (Moretto 1996).

Synonyms. Dugesia rincona Marcus, 1954; D. (G.) rincona Ball, 1974; Girardia rincona Kawakatsu et al. 1984b.

Distribution. Northern Chile (Coquimbo Region), Peru, Venezuela.

Marcus (1954) was the first to describe Girardia rincona based on nine specimens found in Coquimbo Region (Fig. 1, spot 1). The largest specimen measured 12 mm long and 1.5 mm wide. The head was almost round, characteristic of the Dugesia genus and small white protruding auricles. The body was equally broad or expanded in the middle and the posterior end pointed. The dorsal side was grayish brown or grayish yellow, sometimes with a pale midline; the ventral side is white (Fig. 2F, Table 2); the unpigmented pharynx measured up to 2.5 mm long.

A detailed description of the reproductive apparatus (Fig. 3D) was given by Marcus (1954). In summary, numerous testes were located ventrally; sperm ducts were dilated, convoluted and located posterior to the pharynx. Contrary to other Girardia species, no bicuspid seminal vesicle was found. The ovaries were located at the level of the fourth and fifth intestinal branches; ovovitelline ducts (od) unite to form a common duct that opens to the bursal canal (bc), which characterizes the species. However, in this specimen, the female organs were not fully mature.

The species was redescribed by Kawakatsu and coworkers based on material from Peru and Venezuela (Kawakatsu and Mitchell 1984; Kawakatsu et al. 1984b). In these specimens, the sperm ducts give rise to a small seminal vesicle, continuing as a unique and narrow ejaculatory duct (ed). The penis papilla (pp) is short and conical, and accompanied by many eosinophilous glands. The epithelium of the ejaculatory duct is similar to that of G. canai, found in central Chile. However, it differs significantly in other characteristics: the copulatory bursa (cb) of G. rincona is smaller, there are preovaric testicular follicles, extrapenial seminal vesicles run upward to the anterior dorsal side of the penis bulb, among others. Even though the rounded head shape and unpigmented pharynx are characteristic of Dugesia, Ball (1974) listed the species under the genus Girardia, considering the absence of seminal vesicles and the ventral testes.

Synonyms. Planaria patagonica Borelli, 1901; Planaria michaelseni Böhmig, 1902; Curtisia patagonica Kenk, 1930; Curtisia michaelsoni Kenk, 1930; Cura patagonica Ball, 1974; Cura michaelseni Ball, 1974; Dugesia patagonica Ball, 1974.

Distribution. Southern Chile (Magallanes Region), Argentina.

The first description of Romankenkius patagonicus dates from the beginning of the 20^th century. Borelli (1901) described this triclad found in the Argentinean Patagonia near Santa Cruz River and named it Planaria patagonica. He also mentioned that Bergendal (1899) had found a similar sexually immature planarian from a forest stream with almost no vegetation near Punta Arenas, Chile, during the Swedish expedition to Tierra del Fuego (1895–1896). Based only on external description and geography, Borelli considered both to belong to the same species. A year later, Böhmig (1902) described Planaria michaelseni from Picton Island in Tierra del Fuego, Magallanes (Fig. 1, spot 25). Two specimens were collected from under rocks in a freshwater lake, of which only one was sexually mature. The length of the animals was about 5.5 mm, the width 3.5 mm. Böhmig contrasted anatomical characteristics to Borelli’s planarian and suggested that the specimens likely correspond to Planaria torva or Pl. polychroa. Later, the species was renamed under the genus Curtisia (Kenk 1930), and de Beauchamp (1939) suggested that all these specimens correspond to one, Curtisia michaelseni, which was agreed by other authors (Marcus 1954; Kawakatsu et al. 1984a; Sluys et al. 2005). Ball (1974) placed the species in the genus Cura.

Subsequently, expeditions by Haga in 1966 and Inoue in 1971 resulted in the collection of specimens of this species in seven locations in Torres del Paine, Tierra del Fuego (Fig. 1, spots 17–21, and 24), leading to a publication that provided a detailed redescription of the species (Kawakatsu et al. 1984a). Based on differences in the connection between male and female systems, Sluys (1997) determined that C. patagonica and C. michaelseni should be included in the genus Romankenkius. These specimens have ovovitelline ducts (od) uniting to form a common duct that opens into the proximal region of the bursal canal (bc), at the posterior section of the common atrium (Fig. 3E). Later, Sluys et al. (2005) published an article focused on the biogeography of the genus Girardia describing new species, detailing old records and redescribing some species. Despite being focused on Girardia, it offers images, a description and discussion about R. patagonicus comparing samples from Aracena Island, Magallanes (Fig. 1, spot 26), and Gutierrez Lake, Argentina, and contributes to the current understanding of the species. Thus, the range of R. patagonicus, which inhabits cold waters (6–11 °C), extends from Gutierrez Lake, Argentina (41°S) to Cockburn Channel (55°S).

Out of the sixty-five specimens collected in the description of Kawakatsu et al. (1984a), some were fixed in formalin and included small, darkly pigmented individuals. Sexual and non-sexual specimens were obtained, where the sexual ones had dimensions of approximately 6 mm long and 2–3 mm wide, while the sexually immature ones had dimensions of approximately 3 mm long and 1 mm wide, in agreement with Böhmig (1902). The authors mention they found fragments but do not discuss the possibility of asexual reproduction. The head of living animals is moderately rounded with broad ends and white, short, blunt auricular sense organs (Böhmig 1902; Kawakatsu et al. 1984a; Sluys et al. 2005).

The dorsal surface of most of the specimens is covered by spots of a very dark brown or gray color, except for a pale colored median longitudinal line, which starts from the top of the eyes and extends almost to the posterior end of the body (Fig. 2G, Table 2) (Borelli 1901; Böhmig 1902; Kawakatsu et al. 1984a). The ground color is gray or brownish-gray, with preserved animals showed pale-brown or olive-green hues (Böhmig 1902; Sluys et al. 2005). The ventral surface is light gray or whitish with some spots of dark pigment scattered on the surface but very numerous in the anterior cephalic part (Borelli 1901; Böhmig 1902) or uniformly blackish brown with numerous dark colored spots and a short, narrow, whitish, midventral line at the head level (Kawakatsu et al. 1984a). The pharynx is large and unpigmented.

The specimens have a pair of small ovaries located ventrally between the second and third intestinal diverticula, while the testes are located mainly dorsally and pre-pharyngeally (Kawakatsu et al. 1984a). The penis has a moderately large bulb embedded in the parenchyma and a short conical papilla (pp), while the sperm ducts come from mature spermiducal vesicles from the mouth to the anterior level of the penis. The copulatory bursa (cb) is large. The common genital atrium is a wide cavity that goes towards the male antrum in front and towards the female canal dorsally and opens to the genital pore (go) ventrally by a narrow tubular fragment of the antrum.