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In this study, we assembled a complete mitochondrial genome of Codonobdella sp. sample from Lake Baikal, Russia and reassembled third party raw data of Piscicola geometra. Mitogenomes of both fresh...

The Caspian salmon is included in the Red List of Azerbaijan with the international status CR (Critically Endangered). The article presents the comparative analysis of the parasitofauna of the Caspian salmon (Salmo trutta caspius Kessler) during the period of its existence (1955–2015) at the hatcheries of Azerbaijan (Chaykend and Chukhur-Gabala salmon fish hatcheries). When comparing the quantitative index of parasitofauna for the first years after the creation of the salmon fish hatcheries (9 species of parasites) and studies carried out by the authors (7 species of parasites), it was revealed that the change was insignificant. However, significant changes in the species composition of the parasitofauna of the Caspian salmon were found. The parasites Chilodonella piscicola, Trichodina truttae, Eubothrium crassum, Rhabdochona gnedini, Cystidicoloides tenuissima, Piscicola geometra found in the first years of the salmon fish hatcheries were not recorded by the authors, and Bunodera luciopercae, Metechinorhynchus baeri, Pomphorhynchus laevis, Glochidium sp. revealed in recent studies were not observed in the early years. The dominant groups of parasites of the Caspian salmon were revealed. A systematic review of all parasites of salmonids found during this period is presented. Three species of parasites were noted for the first time in the territory of Azerbaijan for the Caspian salmon in the salmon fish hatcheries (trematode Bunodera luciopercae, acanthochephala Pomphorhynchus laevis and mollusk Glochidium sp.). The authors specifically noted parasites identified from 2005 to 2015 that are conditionally pathogenic for the Caspian salmon and capable to cause significant damage to the salmon hatcheries: Costia necatrix, Ichthyophthyrius multifiliis, Gyrodactylus derjavini, Metechinorhynchus baeri, Pomphorhynchus leavis, Bunodera luciopercae. The authors note that during the period of parasitological studies of the Caspian salmon in salmon hatcheries in Azerbaijan, pathogenic parasites for humans have not been found.

Specimens of Piscicola pojmanskae were identified in the macrozoobenthos community in Zostera meadows in Puck Bay. The presented paper is the first report on the observation of this species in the Gulf of Gdańsk (the southern Baltic Sea). Leeches are a rare component of the benthic fauna in this brackish water area.

The toxicity of varying concentrations of T. alnifolia extract on P. geometra (leeches) was investigated. Aqueous crude extract of roots and stem bark of T. alnifolia plant was obtained and concentrations of 5%, 10%, 15% and 20% of extract were made. Twenty-five juvenile C. gariepinus fish were distributed into five tanks of A-control (0%), B (5%), C (10%), D (15%) and E (20%) of herb extract with two replicates all held in static renewal bioassays. Twenty leeches were introduced into each tank and six hourly observations show that leeches were negatively affected by the herb extract. The extract elicited reduction in swimming activity, caused weakness, paleness and death of the leeches. The concentration- response relationship of P. geometra and T. alnifolia extract shows a mortality of 25%, 40%, 70% and 80% and a median lethal time (LT50) of 42h, 30h, 18h and 12h for 5%, 10%, 15% and 20% at 24h exposure respectively. The resulting sigmoid curve had an arithmetic median lethal (LC50) value of 113mg/l and a logarithmic median lethal (LC50) value of 1.72mg/l. Probit mortality of 4.33, 4.75, 5.52 and 5.84 were observed for 5%, 10%, 15% and 2% concentrations. The herb extract did not have any noticeable effect on the fish. Dissolved oxygen was significantly (P

This study investigates the presence of metazoan parasites on tench (Tinca tinca L.) in Lake Uluabat, Turkey. Data were obtained from on-site surveys carried out between April 1998 and January 2000. Six parasite species were identified: Dactylogyrus macracanthus Wegener, 1909; Asymphlodora tincae (Mooder, 1790); Acanthocephalus lucii (Muller, 1787); Ergasilus sieboldi Nordmann, 1832; Argulus foliaceus Linne, 1758; and Piscicola geometra Linne, 1758. Of these species, three were found on gills of the tench: D. macracanthus (prevalence 15.0%; mean intensity 12.10 ±7.39), A. foliaceus (4.2%; 2.67 ±1.51), E. sieboldi (32.1%; 53.88 ±33.96); P. geometra was found on the skin (1.4%; 1.00 ± 0.00); A. lucii in the intestine (2.8%; 1.75 ± 0.58) and A. tincae in the gut and intestine of the host fish specimens (26.4%; 87.70 ± 108.31). In addition, the density of parasite species was determined according to season as well as according to size of the host fish.

An ectoparasite leech Piscicola geometra were found on female roach (Rutilus rutilus) between the anus and lateral line during the biometric measurements for the purpose of monitoring the fish population in Uluabat Lake. P. geometra was previously reported on Carassius gibelio and Tinca tinca from Lake Uluabat. It was understood with this case report that R. rutilus also is a host fish for P. geometra in Uluabat Lake.

The annual cycle of P. geometra breeding activity depends on light, temperature and nutrition. A photoperiod of about 12-12 delays the genital maturation and prevents the incidence of breeding behaviour. A high temperature speeds up the genital maturation and above a threshold ranging from 15 to 17.5 °C it prevents light from acting. Fasting inhibits egg laying because of its immediate action on the clitellar gland activity. It only acts on oogenesis later.

Observations carried out in nature and in laboratory conditions show that the life cycle of P. geometra includes three or four generations per year. The winter population is composed of much bigger leeches than the summer ones.

Cystobranchus virginicus is described from a small series of specimens taken in the Roanoke River, Montgomery Co., Virginia, and is the second definitely known member of its genus in North America. Although this species shows the obvious external characters usually ascribed to Cystobranchus, the details of the reproductive systems are similar to the condition in the allied genus Piscicola, and it is suggested that a reallocation of the species in these nominal genera, on the basis of internal anatomy, might result in a more satisfactory classification. In nearly all of its features, C. virginicus is more similar to Piscicola geometra and P. milneri than it is to C. verrilli, its presumptive North American congener. External key characters used to separate the two "genera" are perhaps only specific in importance. The piscicolid leeches of North America, by contrast with the larger and more abundant glossiphonid and hirudid types, comprise a small and poorly known group of the Hirudinea. Most of our knowledge about them derives from the fairly recent papers of Meyer (1940, 1946); only about ten species-in four genera-are recorded from the entire Nearctic region, and most of them from the central and northeastern sections of the North American continent. It is possible that only a start has been made toward the discovery and classification of our piscicolid fauna, and that a large number of new forms will eventually be recorded. This likelihood is emphasized by the subject of the present paper, which despite being the first piscicolid that I have examined, is unquestionably a new species. About a dozen specimens were recently picked up from an aggregation on a submerged stone and brought in alive by a student at Radford College. Most of these leeches were considerably enlarged over the entire urosome, presumably as a result of recent engorgement. Two specimens in a more normal condition have been cleared in clove oil and studied in connection with Dr. M. C. Meyer's valuable papers; from these and the key characters currently employed in the diagnosis of leech genera, the species must be regarded as an undescribed member of the genus Cystobranchus (but see appended discussion of this subject) . Family Piscicolidae Genus Cystobranchus Diesing Cystobranchus Diesing, 1859, Sitzungber. Akad. Wien, Math.-naturw. kl., 33; 483. Type species: Cystobranchus troscheli Diesing, 1859( = Piscicola respirans Trosched, 1850). Diagnosis.-Piscicolidae with the following combination of characters: body distinctly divided into two regions, the urosome broad, subterete, its somites composed of 7 annulations; 6 pairs of testes; 11 pairs of distinct pulsatile vesicles; body surface without ornamentation