Joanna M. Cichocka

Diversity of features of the female reproductive system and other morphological characters in leeches (Citellata, Hirudinida) in phylogenetic conception

An epistemological–evolutionary conception of leeches (Hirudinida) based on features of the female reproductive system in combination with other morphological characters is presented in the spirit of the cladistic school of taxonomy. Characters relating to the structure of the ovary and the course of oogenesis in leeches were interpreted in this manner, for the first time. Each study was conducted on type species of higher taxonomic groups of true leeches. Results of analyses using features of the reproductive system only as well as in combination with other morphological characters show Piscicolidae and Glossiphoniidae as sister clades making Rhynchobdellida a monophyletic group. Also, Hirudiniformes and Erpobdelliformes appeared to be sister clades within Arhynchobdellida. The relationship between the outgroup specimens and leeches remained unresolved, because both Acanthobdella peledina and branchiobdellidans appeared to be in an equivocal relationship to hirudinidans. Characters concerning the structure of the female reproductive system and course of oogenesis thus appeared to be useful, although conservative, for reconstruction of leech phylogeny, and they well reflect phylogenetic relationships of Hirudinida at the family level.

Coexistence of Placobdella costata (Fr. Müller, 1846) (Hirudinida: Glossiphoniidae) and mud turtle Emys orbicularis

Emys orbicularis is receding from Europe, mainly due to anthropogenic habitat changes. Its parasite, Placobdella costata, is widely distributed within both the former and the present distribution range of the host. Though closely associated with the mud turtle, it may have other hosts (birds, amphibians, reptiles). Its reproductive period coincides with that of its host’s migration to the breeding grounds, thus facilitating dispersal of the parasite. Based on literature data we have analyzed the geographic spread of P. costata and mud turtle to observe the possible overlap of their habitats. Observations on the population of mud turtle and the associated leech species (P. costata) were carried out in eastern Poland — Podlasie Lowland. The studies were conducted in spring and summer in 1986–1993. The leeches were collected from the turtles caught in the water and on land. Observations showed that most leeches were found on turtles inhabiting the lake or moving to a breeding area. The greatest intensity of invasion was observed in June and July and that most leeches were observed in female E. orbicularis characterized by greater length of the carapace and weight, compared with males and juvenile individuals.

The invasion of the leech Piscicola respirans (Hirudinea: Piscicolidae) on the fins of European grayling Thymallus thymallus

This study presents the parasitical relationships between the leech Piscicola respirans and European grayling Thymallus thymallus. It determines leech invasion intensity and extensity as well as describes the preferences of fin selection by the parasite as a place to attach and feed. It also shows the significance of fin selection by the leech in the initial phase of life cycle. Finally, the study defines P. respirans as a predominantly fin-parasite of fishes. Most probably the host-searching mechanism is based on positive phototaxis.

Piscicola siddalli n. sp., a Leech Species from the United Kingdom (Clitellata: Hirudinida: Piscicolidae)

Abstract A new species of fish leech from England, Piscicola siddalli n. sp. (Piscicolidae), was collected in 2006 on stones and on grayling (Thymmallus thymmallus L.) in the River Ure, North Yorkshire, Great Britain. The leech is 4(12) annulate; gonopores are separated by four annuli. The male gonopore is much larger than the female gonopore. Seminal receptacle consists of a round aperture, located at a distance of 3 annuli behind the female gonopore. Copulatory area on the clitellum is in the form of a circle. Vector tissue has the form of a circular plate, below the oviduct opening.

New information on the geographical distribution of Piscicola brylinskae Bielecki, 2001 (Hirudinea: Piscicolidae) in Poland and remarks on its systematic position

For the first time, Piscicola brylinskae was described from Lake Vechten in the village of Bunnik, near Utrecht — The Netherlands. Until now, P. brylinskae has been found in Poland in Lake Maróz and in the Łyna River near Olsztyn (the northern part of Warmian-Masurian voivodeship). Thanks to proper conservation the coloration of P. brylinskae was described for the first time. Applying 32 indexes resulted that P. brylinskae clustered to Caspiobdella fadejewi. Analysis based on 113 non-metric characteristics has shown that P. brylinskae is most similar to Piscicola margaritae. Though, P. brylinskae do not form with P. margaritae dichotomic branching nor with any other species from this cluster, it could confirm that it is an individual species of the Piscicola genus.

Atlantic sturgeon, Acipenser oxyrinchus Mitchill, infected by the parasitic leech, Caspiobdella fadejewi (Epshtein) (Hirudinea; Piscicolidae), in the Drwêca River

Atlantic sturgeon, Acipenser oxyrinchus Mitchill, infected by the parasitic leech, Caspiobdella fadejewi (Epshtein) (Hirudinea; Piscicolidae), in the Drwęca River This study presents the parasitic relationship between the leech, Caspiobdella fadejewi, and the juvenile Atlantic sturgeon, Acipenser oxyrinchus. The aim was to determine leech invasion intensity and extensity and describe parasite feeding location preferences on the ventral side of the snout and gill cavities. The prevalence of C. fadejewi occurrence was 37.3%, at an intensity of one to eight leeches. It was confirmed that the intensity of leech occurrence was positively correlated with sturgeon total length (r=0.545, P<0.05, N=15). The host-searching mechanism is most probably based on positive phototaxis. This is the first record of C. fadajewi from A. oxyrinchus. The leech was first observed during routine examinations of sturgeon collected in June 2008. The leeches were usually attached to the inside lower portion of opercula near the isthmus. Zarażenie jesiotra Acipenser oxyrinchus Mitchill pasożytniczą pijawką Caspiobdella fadejewi (Epstein) (Hirudinea; Piscicolidae) w Drwęcy Słodkowodne gatunki pijawek pasożytujące na rybach (Piscicolidae) jako monofiletyczna rodzina, z nielicznymi wyjątkami, zamieszkują wody kontynentalne Holarktyki. W pracy scharakteryzowano występowanie pasożytniczej pijawki Caspiobdella fadejewi u juwenalnych jesiotrów Acipenser oxyrinchus Mitchill. Określono ekstensywność oraz intensywność zarażenia jesiotrów wpuszczonych do Drwęcy. Ekstensywność występowania C. fadejewi wynosiła 37,3%, a intensywność od 1 do 8 pijawek. Stwierdzono, że intensywność występowania pijawek była dodatnio skorelowana z długością całkowitą jesiotrów (r=0,545, P<0,05, N=15). Pijawki najczęściej były zlokalizowane na płetwach parzystych lub rostrum, rzadziej na bokach ciała, płetwach odbytowej lub ogonowej. Prawdopodobnie odszukiwanie żywiciela związane jest z pozytywną fototaksją. Pijawki wykorzystują w odszukiwaniu żywiciela jego cień, który powoduje spadek natężenia światła odbierany przez plamki oczopodobne znajdujące się na przyssawce tylnej.

Environmental factors determining the distribution pattern of leeches (Clitellata: Hirudinida) in large river systems: A case study of the Oder River system

Abstract The largest rivers in Europe are under strong human pressure, resulting in habitat changes and consequently in structural changes in the quantitative and qualitative composition of fauna assemblages. The aim of this study was to identify the taxonomic structure of leech assemblages and the main environmental factors influencing their distribution pattern on a 306 km stretch of the Oder River encompassing different habitat types. Representatives of 28 leech taxa were recorded in 527 samples of bottom macrofauna. The most abundant and most frequently recorded species was the eurytopic Erpobdella octoculata, occurring in all examined habitat types. Although a significant influence of habitat type on the species composition of leech assemblages was noted, a significant positive correlation with habitat type was found only in the case of Piscicola pojmanskae and P. geometra. Our results show that abundance of food resources was the most important factor influencing the distribution of leeches.

Leeches (Clitellata: Hirudinida) of an upland stream : taxonomic composition in relation to habitat conditions

Abstract Hirudinida comprise a constant component of benthofauna in running waters and their taxonomic composition is often analyzed to evaluate the environmental quality. However, the indicatory role of particular species is still arguable. Thus, it is very important to provide more detailed information on the impact of environmental parameters on the species structure within this group of invertebrates. Representatives of nine species were found in the investigated upland stream including mainly Erpobdella vilnensis and E. octoculata. The research has demonstrated that the hydromorphological conditions and feeding behavior are the main factors determining the taxonomic composition of leeches in particular sections of a watercourse.

Phylogenetic utility of the geometric model of the body form in leeches (Clitellata: Hirudinida)

Abstract Architectonics of the leech body constitute a source of promorphological characters which have been used for modeling. A geometric model of the leech body form was applied in a phylogenetic analysis for the estimation of the utility of morphometric data in the reconstruction of the history of Hirudinida. A cladistic analysis included species representing all main ecological groups of leeches. In the analysis the morphometric data were used as non-discretized mean values and as mean values coded with the gap-weighting method. Obtained phylogenetic trees were compared with cladograms generated based on combined data sets including discrete qualitative morphological characters as well as known molecular phylogenies of leeches. The study demonstrates that the morphometric characters provide additional evidence for the confirmation of monophyletic groups within Hirudinida. Thus, the morphometric data resulting from the geometric model of the leech body form appeared to be applicable for the reconstruction of leech phylogeny

Occurrence of the medicinal leech (Hirudo medicinalis) in birds' nests

Occurrence and breeding of Hirudo medicinalis were recorded in birds’ nests in the fishing ponds and water bodies used extensively by anglers in south-eastern Poland, in 4 of 11 studied bird species (Circus aeruginosus, Fulica atra, Cygnus olor, Chroicocephalus ridibundus). Factors important for the distribution and density of this leech were: nest height, pH of the water and oxygen concentration in the water inside the nests, the body-length of the nesting birds. Our data show that (1) H. medicinalis chooses nests as habitats that are safe in water bodies rich in predators (particularly fish) and provide stable feeding conditions; (2) fishing ponds and other water bodies used extensively by anglers in a landscape modified by human pressure can be an important secondary habitat for the medicinal leech. As the nesting activity of some aquatic birds apparently favors the occurrence of H. medicinalis, active protection of aquatic birds and creating sites appropriate for their breeding may be an indirect way for the conservation of the leech in such areas.