[Bradophilidae fam. n.--a new family of mesoparasitic copepod (Copepoda: Poecilostomatoida), collected from the polychaete Brada villosa from the Beloe more]. / Bradophilidae fam. n--novoe semeistvo mezoparaziticheskikh veslonogikh (Copepoda: Poecilostoma toida), naidennykh na Brada villosa v Belom more.

The Bradophila pigmaea Levinsen, 1878 is redescribed on the basis of new material collected firstly after original description. The new family Bradophilidae belonging to order Poecilostomatoida is erected on the basis the genus Bradophila. The male of Bradophyla pigmaea is described in detail at firstly.

[The peculiarities of parasitism in the copepoda and rhizocephala]. / Osobennosti parazitizma veslonogikh i kornegolovykh rakov.

In the parasitology it is accepted to subdivide the parasites into two categories based on their spatial relations with the organism of a host. To first category--ectoparasites--includes organisms, which live "on external covers, on a skin, on gills". To the second category--endoparasites--includes organisms living "in internal cavities, tissues and cells of the host" (Dogiel, 1941). Feizullaev (1971) offered the third category--mesoparasites--where he placed "the parasites inhabiting places, which are connected to cavities being open to external environment". According to him the places are oral, nasal, eye cavity, cloaca etc. Since some parasitic copepods living in certain kind of interrelation with a host can be referred neither to ectoparasites nor to endoparasites, the author offers these following criteria for the mesoparasitism definition. 1. Morphological and anatomic subdivision of the body of the parasite into two main parts: ectosoma located in the external environment (environment of the second order) and endosoma located inside the organism of the host (environment of the first order). 2. Functional subdivision of parasite body into two parts: endosoma which performs the trophic function and ectosoma with genital organs performs the reproduction function. 3. Existence of the parasite on the border of two environments (of the first and second order) which have an influence on parasite directly and simultaneously. The mesoparasites are known among the parasitic Copepoda and Rhizocephala only. As for the copepods all members of the family Herpyllobiidae may be placed in this category; the members of the families Phyllodicolidae and Chitonophilidae may be also included in it, albeit tentatively (because their anatomy has not yet been adequately studied), as well as five genera of the family Nicothoidae (Aspidoecia, Cephalorhiza, Diexanthema, Nicorhiza and Rhizorhina), and Bradophyla pigmaea.

[Some peculiarities of the relationships between parasitic copepods and their invertebrate hosts]. / Nekotorye osobennosti vzaimootnoshenii paraziticheskykh veslonogikh i ikh bespozvonochnykh-khoziaev.

According to the rule of academican E. N. Pavlovskiy, any organism of host is an environment of inhabit for a parasite (Pavlovskiy, 1934). It was analysed, which "ecological niche" or microbiotop (= microhabitat) is occupied by this or that species of symbiotic (parasitic) copepods in organisms of different groups invertebrate-hosts. The assumption lying in a basis of the given analysis means that each group of hosts may give to cohabitants only certain variants of microbiotopes independently on the general morphological structure and life mode of hosts. Five types of microbiotops offered by various groups of hosts for symbiotic copepods are designated (Ta[symbol: see text] 2). 1. The body surface of benthic invertebrates as a microbiotope is characterized by conditions being little different (concerning any kind of physical and chemical influences on copepods) from those in external environment on any other substrate. Apparently a trophical dependence plays a determining role in this case. There are certain directions in a development of adaptations, which are characteristic in some extent for all water ectoparasitic crustaceans and have one functional task--to help to an ectoparasite to keep itself on a surface of host body. In the first, the maxillules and maxillipeds significantly are developed, they get a form of large claws, with which the dopepods are strongly attached on a surface of host body and have an opportunity to move on it without a danger to be washed off. In the second, the form of the body undergoes a dorso-ventral expression and expansion of prosome, forms a cephalic shield allowing to the symbiont to press itself tightly to the host body surface and to avoid the loss of host (tab. 2). In occasions, some ectoparasites stimulate the formation of galls in skin tissues of the host, that also provides the parasite with constant conditions, without any threat to lose the host. However, this phenomenon has not a wide distribution and is observed in some groups of crustacean and echinoderm hosts. 2. The narrow tubular cavities in the organism of host either they are a part of external environment (as in channel system of spongia) or a part of internal environment of organism (as channels of blood system or thin parts of a digestive system) have always rigidly limited sizes and form. Characteristics of all parasites occupying this microbiotopes are the strong transformations. They are expressed by the reduction of legs or any other appendages (frequently in a significant degree), loss of segmentation to some extent and in eruciform (or vermiform) form of a body (tab. 2). This microbiotope is occupied by an ectoparasite in one case only (Spongicola uncifer from channel system of spongia) and by endoparasites in all other cases. 3. Large cavities connected with external environment. The formations of various genesis, such as mantle cavity of molluscs, gill cavity and marsupium of crustaceans, bursal cavity of ophiuroids and branchial cavity of ascidians, concern this type of microbiotopes. All of them are characterized by the relative difference from the external environment and rather large volume (in comparison to sizes of copepods), that provides the parasites with a sufficient protection from factors of the external environment and constant source of food such as elements of host body or food's particles brought by the water flow. Morphological changes in inhabitants of the microbiotope have two directions. They practically are absent in the overwhelming majority copepods, living in the mantle of cavity of the lamellibranches. On the other hand, the inhabitants of gill cavity and marsupium of crustaceans, bursal cavities of ophiuroids and branchial cavity of ascidians are characterized by the presence of strong transformations. Usually there are expressed in a loss of segmentation to some extent, reduction of appendages and swelling of body, as in species of the genus Sphaeronella (tab. 2). Changes are also observed in the life cycle: the tendency to reduce stages of development (development of nauplii stage, which takes place under the ovarial cover). In this case the copepodid stages hatch from the ova. 4. The internal cavity of organism of host. This type of microbiotopes in different groups of the hosts is represented in a various degree. We recognise it in a coelome of polychaetes, lacunar system of molluscs, mixocoel of crustaceans, coelome of echinoderms and cavity of body in ascidians. Two basic evolutionary directions are observed in copepods occupying this microbiotope. In the first case, the parasite is not exposed to transformations and keeps the initial plan of structure as in ancestral free-living forms. In the second case the parasites are exposed to strong transformations, they either live directly in cavity's liquid, or are surrounded by a cyst (as in Cucumaricolidae). 5. Microbiotope of the last type is most specific. The simultaneous existence in two environments--external environment (environment of the second order) and internal environment (environment of the first order) leads to the complete loss of ancestral type in a structure and level of organisation. At the same time both morphological and functional division of the parasite body into two parts produces a new formation--the ectosome and endosome. In this case we deals with the phenomenon of mesoparasitism.

[Structure of the epithelium of the parasitic turbellaria Notenera ivanovi (Turbellaria: Fecampiida)]. / Stroenie épiteliia paraziticheskoi turbelliarii Notenera ivanovi (Turbellaria: Fecampiida).

The ultrastructure of the epithelium in Notentera ivanovi (Turbellaria, Fecampiida) has been studied. Notentera ivanovi lacks the digestive system but has a pad of the epidermal cells on the dorsal side of the body, which seems to be similar to the digestive epidermis on LM. Both the ventral and dorsal epithelium are cellular, ciliated and not insunk (fig. 1, a). The ultrastructure of the ventral and dorsal epithelium is similar in essential features. The cells bear abundant microvilli, cilia and are very rich in mitochondria, but the cytoplasm does not contain lysosomes and shows no other indications of phago- or pinocytosis. The basal membrane of epithelial cells forms deep invaginations (fig. 1, [symbol: see text]), partly with dilations (fig. 1, a; 2, a) containing the lamellated material (3, [symbol: see text]). In the basal part of the cells the numerous Golgi apparatus and rare cysternae of the smooth endoplasmic reticulum were observed (fig. 2, a, [symbol: see text]). The epithelium consists of several types of cells, which differ in the structure of secretory granules. The most abundant type of cells contains the granules with the rough-fibrillated content (fig. 1, a; 2, [symbol: see text]; 3, a). The cells of this type cover most part of the body. In some cells the content of such granules becomes condensed and electron-dense granules appear (fig. 3, a, [symbol: see text]). Another type of cells contains the giant granules with the rough-fibrillated content (fig. 3, [symbol: see text]). Third type of the secret is the granules with the finely fibrillated content which is ejected by exocytosis. The cells of the second and third types form a separate areas of the epithelium of the dorsal side of the body but occasionally were observed in the ventral epithelium too. The epithelium of N. ivanovi differs from that in Kronborgia by the abundance and diversity of secretory contents. The role of the epithelium in the digestion remains conjectural. It seems to be mainly the suckering tissue transporting the low molecular nutrients.