Placobdella akahkway Fan & Carle & Kvist 2022, n. sp.
Creators: name: Fan, Sophia L.
name: Carle, Danielle De
name: Kvist, Sebastian
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Annelida
Clitellata
Rhynchobdellida
Glossiphoniidae
Placobdella
Placobdella akahkway

description: Placobdella akahkway n. sp.
Figures 2–5
Placobdella sp. 1; de Carle et al., 2017
Diagnosis. This species can be distinguished from all of its congeners on the basis of its possession of both compact and diffuse salivary tissues. Moreover, the large size of this species, the dorsal pigmentation patterning in combination with the papillation pattern, and its geographic distribution might all lend themselves well to separating this species from other members of the genus. See Figure 2 for imagery of the external morphology for type specimens.
Holotype. ROMIZI11495, whole specimen, undissected, in 95% EtOH; from type locality, collected on June 23, 2016, by SK and Charlotte Calmerfalk Kvist; holotype COI GenBank accession number OL743155.
Type locality. Adams Lake, Cypress Hills Provincial Park, Saskatchewan, Canada (49°38.551’N, 109°50.231’W). From rocks in shallow water on east side of lake.
Paratypes. ROMIZI11494, whole specimen, undissected, all in 95% EtOH; from type locality, collected on June 23, 2016, by SK and Charlotte Calmerfalk Kvist. Three remaining paratypes dissected: ROMIZI11247 from Big Island Lake, Alberta. (53°29.623’N, 113°11.831’W), collected on June 25, 2016, by SK and Charlotte Calmerfalk Kvist; ROMIZI11464, with brood, from unnamed pond, Blue Heron Provincial Park, Saskatchewan. (53°44.903’N, 105°53.075’W), collected on June 19, 2016, by SK and Charlotte Calmerfalk Kvist; ROMIZI11542 from unnamed pond east of Lake Winnipeg, Manitoba. (50°43.371’N, 96°32.349’W), collected on June 8, 2016 by SK and Charlotte Calmerfalk Kvist. All specimens with small part of posterior sucker removed for DNA sequencing.
Other material examined. In addition to the type series, several specimens collected across Alberta, Saskatchewan and Manitoba were examined (Table 1). As part of a previous study of the bacterial symbionts of these leeches (i.e., Manglicmot et al., 2020), the bacteriomes for all of these specimens were removed, such that none of the specimens is fully intact.
Etymology: “ akahkway ” is the Plains Cree word for “leech” in honour of the Indigenous language group spoken at this species’ collection sites (including the type locality) in eastern Alberta and western Saskatchewan, Canada.
Description. Description based on five specimens (two fully intact and three dissected specimens). Body dorsoventrally flattened, oval to lanceolate with anterior and posterior tapering and widest at midsection. Anterior end markedly narrower than posterior end. Rather variable colouration, ranging from olive brown, reddish/pinkish brown, to darker greyish brown (Fig. 2). Mid-dorsal stripe dark brown and irregularly interrupted; continues past mid-body and ends well before posterior end. Venter beige and without pigmentation or patterning. Average body length 5.27 cm (holotype 5.30 cm), with minimum length 1.0 cm (exception being juvenile specimens at 0.4–0.5 cm) and maximum length 5.5 cm. Average body width at male gonopore 2.10 cm (holotype width 3.10 cm). Complete somites triannulate with partially subdivided annuli throughout (Fig. 3). Somites I and II uniannulate; III and IV biannulate: V–XXIII triannulate; XXIV–XXV biannulate; XXVI–XXVII uniannulate. Two pairs of eyespots on III first annulus (a1) in placobdelloid arrangement (Fig. 4A). Anus dorsal on XXVII (Fig. 4B). Oral sucker 0.5 cm in diameter with mouth pore on anterior border (Fig. 4C). Posterior sucker circular with dorsal papillae (Fig. 4B). Five main rows of papillae: 1 medial, 2 paramedial, and 2 lateral. Smaller papillae interspersed outside of main rows, becoming more conspicuous towards posterior end. Throughout body, dorsal papillae punctiform with most prominent papilla on a2. Male gonopore at XI/XII (Fig. 4D). Female gonopore at XII a2/a3 (2 annuli between gonopores) (Fig. 4D).
Internal body cavity with abundance of dark chromatophores scattered randomly. Relatively large proboscis in membranous sheath, extending linearly and posteriorly to XI a1 (Fig. 5). Salivary glands arranged in both a single pair of compact salivary glands and diffuse salivary tissue (Fig. 5). Compact salivary glands (posterior pair) in distinct lobes, extending from IX a3-XI a3 and arranged on either side of proboscis. Diffuse salivary glands (anterior pair) interspersed in tissue, concentrated anteriorly and extending from VIII–XI, less concentrated posteriad. Salivary ductules extending from diffuse glands attached to base of proboscis. Esophagus short and folded (Fig. 5). Bacteriomes arranged as blind sacs, extending anteriorly from esophagus and folded behind proboscis at X a 2 in one paratype (Fig. 5). Crop with seven pairs caeca, last pair extending posteriorly to form well-developed post caeca. Intestine with four pairs simple caeca. Male atrial cornuae well-developed with highly coiled ejaculatory ducts (Fig. 6). Testisacs in six pairs, intersegmental, from XIII/XIV– XVIII/XIX. Ovaries curled; ovisacs anteriorly bilobed and without common oviduct (Fig. 6). Anterior ovisac bifurcation at XII/XIII, anterior lobe extending anteriorly to XII and posteriorly to XIV (Fig. 6).
Geographic distribution. The species is known from the following lakes and ponds (Fig. 1): Muir Lake, Alberta (53°37.680’N, 113°57.393’W); Half Moon Lake, Alberta (53°27.351’N, 113°05.010’W); Big Island Lake, Alberta (53°29.623’N, 113°11.831’W); Beaver Lake, Alberta (54°45.400’N, 111°55.287’W); Adams Lake, Saskatchewan (49°38.551’N, 109°50.231’W); Cherry Lake, Saskatchewan (50°23.640’N, 103°39.571’W); unnamed pond in Blue Heron Provincial Park, Saskatchewan (53°44.903’N, 105°53.075’W); Namekus Lake, Saskatchewan (53°50.320’N, 106°02.826’W); Adam Lake, Manitoba (49°02.607’N, 100°03.631’W); unnamed pond East of Lake Winnipeg, Manitoba (50°43.371’N, 96°32.349’W). The distance between the western-most and eastern-most collecting localities (as the crow flies) is roughly 1,230 km.
Remarks. Despite its relatively non-ornate external appearance compared to other select members of this genus [see e.g. Placobdella parasitica (Say, 1824)], this species displays rather variable sizes and colourations across examined specimens. The three dissected specimens show varying amounts of development of reproductive organs, despite similar overall body sizes.
Placobdella akahkway closely resembles Placobdella kwetlumye Oceguera-Figueroa, Kvist, Watson, Sankar, Overstreet & Siddall, 2010 in overall external appearance but can be separated from this species by the presence of both compact and diffuse salivary tissue (P. kwetlumye does not possess diffuse salivary tissues). In addition, P. akahkway is considerably larger than P. kwetlumye (average body length 5.27 cm versus 1.77 cm). Finally, the geographic distributions of the species do not seem to overlap, and the known ranges of each species are separated by a substantial geographic barrier (the North American Cordillera). Distribution might therefore aid in future identifications of specimens.
description: Published as part of Fan, Sophia L., Carle, Danielle De & Kvist, Sebastian, 2022, Placobdella akahkway n. sp. (Clitellata: Hirudinea: Glossiphoniidae), a new leech species from central Canada, pp. 265-280 in Zootaxa 5159 (2) on pages 270-273, DOI: 10.11646/zootaxa.5159.2.5, http://zenodo.org/record/6777158