Infection of Slugs with Theronts of the Ciliate Protozoan, Tetrahymena rostrata

Tetrahymena rostrata is a free-living ciliated protozoan and is a facultative parasite of some species of terrestrial mollusks. It is a potential biopesticide of pest slugs, such as the grey field slug, which cause considerable damage to crops. T. rostrata has several developmental forms. Homogeneous preparations of the feeding stage cells (trophonts) and excysted stage cells (theronts) were compared for their ability to infect and kill Deroceras reticulatum slugs. Theronts were more effective and remained viable and infective, even after prolonged starvation.

INTRA- AND INTERPOPULATION SHELL VARIABILITY OF TERRESTRIAL MOLLUSC BREPHULOPSIS CYLINDRICA FROM THE NORTHERN BLACK SEA COAST REGION

The study of the limits of variability of terrestrial mollusks in natural populations and the distribution of the whole spectrum of variability into genetic and ecological components is one of the most important tasks of evolutionary ecology and ecogenetics of these organisms. The authors who studied the malacofauna of this species have repeatedly pointed to the wide range of geographical (interpopulation) variability of conchological characteristicsof mollusks of the genus Brephulopsis. Of particular interest are the features of the populations of the Northern Black Sea coast of Ukraine, where this species is widespread and occupies a variety of geoclimatic characteristics of the territory. The population of the species was first discovered near Lake Solonets-Tuzla near the village Rybakivka of the Berezansky districtof the Mykolaivregion.Based on the measurementsdataof the shell from the first detected population of B. cylindrica from the vicinity of Lake Solonets-Tuzla (C), the limits of variability of traits were determined. The maximum indicator of the width of the shell from the population of Solonets-Tuzla was the largest among those known in the region, thus influencing the conchological characteristics of the species as a whole.Ithas beenconfirmed that shell indicators are under close genetic control within each individual population. In terms of apex height, no significant differences found between all studied populations. Apex indicators are under a high level of genetic control.The study of conchological indicators of each newly identified population of terrestrial mollusks allows clarifying the identification indicators of the species. Microevolutionary processes in B. cylindrica populations of the Northern Black Sea coast are active, specific and depend on localization factors. The variety of conditions contributes to the intensification of evolutionary processes in populations and the acquisition of significant differences in conchological characteristics. There is a tendency to approximate the absolute values of shell height in populations located in similar geoclimatic conditions that affect growth processes.Key words:Northern Black Sea coast, Brephulopsis cylindrica, local population, intrapopulation variability, interpopulation variability,shell. Вивчення меж мінливості наземних молюсків уприродних популяціях та розподіл всього спектру мінливості на генетичну та екологічну складові є однією із найважливіших задач еволюційної екології та екогенетики цих організмів. Автори, які вивчали малакофауну цього виду, неодноразово вказували на широкі межі географічної (міжпопуляційної) мінливості конхологічних ознак представників молюсків роду Brephulopsis, що відіграє значну роль у дослідження еволюційних процесів. Разом з тим, зміни екології молюсків являє собою екстраполяцію екологічних змін макроценозу. Особливий інтерес викликають особливості популяцій Північного Причорномор’я України, де цей вид поширений і займає різноманітні за своїми гео-кліматичними характеристиками території. Популяція виду була вперше виявлена поблизу оз. Солонець-Тузли біля с. Рибаківка Березанського р-ну Миколаївської області.На основі даних вимірювань черепашки з вперше виявленої популяції В. cylindrica з околиць оз. Солонець-Тузли (С) визначено межі мінливості ознак. Максимальний показник ширини черепашкиіз популяції Солонець-Тузли виявився найбільшим серед відомих в регіоні, таким чином впливаючи на конхологічні характеристики виду загалом.Підтверджено, що показники черепашки знаходяться під ретельним генетичним контролем в межах кожної окремої популяції. За показниками висоти апекса не виявлено статистично достовірних відмінностей між всіма дослідженими популяціями. Показники апекса знаходяться під високим рівнем генетичного контролю.Дослідження конхологічних показників кожної нової виявленої популяціїназемних молюсків дозволяє уточнити ідентифікаційні показники виду. Мікроеволюційні процеси в популяціях B. cylindricaПівнічного Причорномор’я активні, специфічні та залежать від факторів локалізації. Різноманіття умов сприяє активізації еволюційних процесів упопуляціях та надбанню значних розбіжностей за конхологічними ознаками. Відмічається тенденція до наближення абсолютних показників висоти раковини у популяцій, розташованих в схожих геокліматичних умовах, які впливають на ростові процеси.Ключові слова:Північне Причорномор’я, Brephulopsiscylindrica, локальна популяція, внутрішньопопуляційна мінливість, міжпопуляційна мінливість, черепашка.

ECOLOGY AND PATHOLOGY OF TERRESTRIAL MOLLUSKS OF THE INTERMEDIATE HOST PROTOSTRONGYLUS SPP.

This paper presents the results of studies of the population of land mollusks of different biotopes, depending on the relief features of the area and the infestation of mollusks with larvae of pulmonary nematodes. The infestation of mollusks with Protostrongylidae larvae in the steppe zone was only 338, including 160 mollusks with Protostrongylus spp. (13.3%) from the number of 1200 mollusks studied. The number of infected mollusks with Protostrongylidae larvae in areas around water bodies was only 535 specimens, including 192 specimens with Protostrongylus spp. larvae (16.3%), in woodlands this figure was 350 specimens with Protostrongylidae larvae, including 130 with Protostrongylus spp. larvae (13.0%). In lowland meadows was 400 copies of mollusks with Protostrongylidae larvae, and 180 copies with Protostrongylus spp. larvae (13.8%). A high percentage of shellfish infected with the larvae of Protostrongylus spp. set in rural pastures 440 (21.0%). A relatively high percentage of infestation in mollusks in areas around reservoirs is 5 specimens per 1 mollusk. The intensity of invasion (II) is the highest in mollusks uncovered in presell pastures and amounted to 9 larval specimens; the lowest intensity of invasion in woodland mollusks is 1 specimen per 1 mollusk.

Mollusks as Indicators of the State of Soil and Water in Uzbekistan

The work examines the vital activity of mollusks. About 160 species of terrestrial mollusks have been identified in Uzbekistan. It has been established that 12 species of terrestrial mollusks live on the plains in the steppe serozem soils at heights. Psychromezobionts live in hydromorphic soil among turf and under stones. Typical and dark soils are home to over 20 species of mollusks. On brown, brown-mountain-forest, light-brown meadow-steppe soils, 4 species of endemic mollusks live. Brackish-water mollusks were also found, which are divided into eurygane, living in a wide range of water salinity, and stenohaline, living in a narrow range of water salinity. Mollusks-indicators of the type and condition of the soil have been determined. In conclusion, the author concludes that it is necessary to further study the species composition and indicator role of mollusks in Uzbekistan.

Annotated checklist of the terrestrial mollusks (Mollusca: Gastropoda) from Hispaniola Island

The annotated checklist on the extant terrestrial mollusks from Hispaniola Island based on literature from 1758 to 2020 is here presented. We report 612 taxa distributed in three subclasses, 129 genera and 39 families. The most representative families are Annulariidae with 26 genera and 233 species, and Urocoptidae with 14 genera and 104, respectively. As more information is produced from the different families reported, these numbers can vary considerably.

Four records of new to Egypt gastropod species including the first reported Tropical Leatherleaf slug Laevicaulis alte (d’A. de Férussac, 1822) (Pulmonata: Veronicellidae)

A survey of terrestrial mollusks was performed during their activity season in various spots of gardens, nurseries and agricultural fields in Cairo, Giza as well as in some neighboring areas between December 2014 and October 2018. Several invasive terrestrial gastropod species were identified. These gastropods are invasive and abundant pests causing considerable and serious damage to agricultural areas in the Nile Delta Region of Egypt. The specimens were collected from different locations in the governorates of Cairo and Giza. A total of 12 species (8 species of terrestrial snails and 4 of slugs) were identified by their shell characteristics and genital-anatomical characters. The following four species were identified for the first time in Egyptian gardens and nurseries: 1) Polygyra cereolus (Megerle von Mühlfeld, 1816), 2) Oxychilus cf. cellarius (O. F. Müller, 1774), 3) Zonitoides arboreus (Say, 1816) and 4) Laevicaulis alte (d’ A. de Férussac, 1822), which is particularly injurious to agricultural production. The other invasive species reported in this study were recorded in other agricultural fields and are common pests of gardens, nurseries and agricultural areas in Egypt. This study presents essential information on each species, their original and current distribution in Egyptian agricultural fields.

New finds of anthropochoric species of terrestrial mollusks in western Ukraine

New finds of 7 anthropochoric species (Oxychilus draparnaudi, O. translucidus, Krynickillus melanocephalus, Monacha cartusiana, M. fruticola, Cepaea nemoralis, C. hortensis) made in Lviv and Ivano-Frankivsk regions in 2019 are listed. The first findings of C. nemoralis in Ternopil region (2017) and C. hortensis in Khmelnytsky region (2016) are also described.

Ecological plasticity of Echinococcus granulosus Batsch, 1786; Rud., 1801 eggs in the Mountainous Zone of Kabardino-Balkaria

The purpose of the research is to study the ecological plasticity of the eggs of Echinococcus granulosus in the mountainous zone of Kabardino-Balkaria. Materials and methods. In the conditions of biotopes in the foothill zone, we set up experiments to determine the timing of development of the eggs of E. granulosus Batsch, 1786; Rud., 1801. The experiments were carried out using fresh eggs washed from the uterus of the indicated cestode. Egg samples in the amount of 10–15 thousand put on the experimental site monthly from March to November. For this, the eggs of E. granulosus were placed in glass jars, which were then placed on the biological site. To determine the viability of infective elements, samples of soil, water, faeces, hay, silage, and compound feed with parasite eggs were taken daily. In each case, 100 eggs from these samples were examined under a microscope. The possibility of overwintering E. granulosus eggs was studied in the mountainous zone. At the end of November, eggs of E. granulosus were added to samples of soil, water, faeces, hay, silage, and compound feed and left during the winter until March of the next year in the external environment. At the end of the winter period, these samples were examined by ovoscopy methods. The data were processed statistically. Results and discussion. It has been established that the timing of reaching the infective stage by E. granulosus eggs in dog feces samples is in direct proportion to the ambient temperature. In March, at an average air temperature of 3.2 ºС, helminth eggs reach the infective stage in 27 days, in June and August – 7–9 days. In autumn, with a decrease in temperature, the maturation of the eggs of the parasite slows down. In September (20.6 ºС), the maturation of eggs to the infective stage was noted in 12 days, in November (8.0 ºС) – in 21 days. 28.0; 22.6; 37.4; 81.6; 74.2 and 92.6% of E. granulosus eggs, respectively in samples of soil, water, faeces, hay, silage and compound feed, retained their viability during the winter. On the distant pastures of Kabardino-Balkaria at an altitude of 1000, 1500, 2000, 2500 m above sea level, 3.2–7.6 times more E. granulosus eggs overwinter in the body of terrestrial mollusks than in the soil, which confirms the fact of their active mechanical participation in the contamination of pastures with infective elements and in the implementation of the epizootic process.