Topic
Haptor
About: Haptor is a research topic. Over the lifetime, 246 publications have been published within this topic receiving 2938 citations.
Papers published on a yearly basis
Papers
TL;DR: This chapter focusses on a group of parasitic platyhelminths generally referred to as monogenetic trematodes, where a few monogeneans are viviparous and the newly-born young resemble the parents, but most are oviparate, and the Newly hatched young is a larva and called an oncomiracidium.
Abstract: Publisher Summary This chapter focusses on a group of parasitic platyhelminths generally referred to as monogenetic trematodes. A few monogeneans are viviparous and the newly-born young resemble the parents, but most are oviparous, and the newly hatched young is a larva and called an oncomiracidium. Most oncomiracidia are partly covered externally with cilia, but some are without cilia. At its posterior end, the oncomiracidium invariably bears an adhesive organ or haptor in the form of a ventrally-directed disc or cup. A gut is present in all of the oncomiracidia. The osmo-regulatory system of larval monogeneans has flame cells and efferent ducts. The larval alimentary canal and nervous system foreshadow the adult condition, but the patterns of external ciliation and of the osmo-regulatory system may reflect phylogenetic development. The study of development of haptor yielded useful clues to evolutionary trends in monogeneans. Further development now took one of two main directions––that is, to elaborate the hamuli and abandon the marginal hooks and to replace some of the marginal hooks with new muscular adhesive organs that are essentially adult features, leaving the hamuli as largely postoncomiracidial, preadult organs. The elaboration of the hamulus apparatus took place by doubling the number of hooks, by incorporating accessory sclerites, or both. The replacement of marginal hooks by adult muscular organs took place in a variety of definite patterns, and if the parasites are arranged according to these patterns, there is a conspicuous correlation between these groupings and groups arranged according to hosts.
172 citations
TL;DR: The main trends in monogenean evolution are traced from a hypothetical skin-parasitic ancestor on early vertebrates, with special consideration given to diversification and specialization of the haptor for attachment to skin and transfer from host to host.
156 citations
TL;DR: The generic diagnosis is amended to include previously unused characters like the path of tendons in the haptor from extrinsic muscles in the body, the presence and form of a marginal valve, the shape of the anterior attachment organs, and the arrangement of musculature at the posterior end of the penis sac.
Abstract: Neobenedenia Yamaguti, 1963, a genus of capsalid (benedeniine) monogeneans lacking a vagina, is redefined. The generic diagnosis is amended to include previously unused characters like the path of tendons in the haptor from extrinsic muscles in the body, the presence and form of a marginal valve, the shape of the anterior attachment organs, the arrangement of musculature at the posterior (proximal) end of the penis sac and the presence of a pair of sphincters in the female reproductive tract. On this basis, the generic composition is reduced from 10 to six species. Species considered valid are: N. melleni (MacCallum, 1927) Yamaguti, 1963; N. adenea (Meserve, 1938) Yamaguti, 1963; N. isabellae (Meserve, 1938) Yamaguti, 1963; N. longiprostata Bravo-Hollis, 1971; N. muelleri (Meserve, 1938) Yamaguti, 1963; N. pacifica Bravo-Hollis, 1971. Neobenedenia girellae (Hargis, 1955) Yamaguti, 1963 and N. paragueraensis Dyer, Williams and Bunkley-Williams, 1992 are considered synonyms of N. melleni. Species formerly a...
109 citations
TL;DR: The Dasybatotreminae is amended to accommodate the new genus Peruanocotyle chisholmae n.
Abstract: Peruanocotyle n. gen. is proposed to accommodate Peruanocotyle chisholmae n. sp. (Monogenea: Monocotylidae). The new species is a gill parasite of the diamond stingray, Hypanus dipterurus (Jordan Gilbert) (Myliobatiformes: Dasyatidae), a demersal chondrichthyan collected off the coast of Callao, Peru. Peruanocotyle n. gen. is placed in the Dasybatotreminae Bychowsky, 1957 because its anterior attachment organ has multiple glandular openings. Peruanocotyle chisholmae n. gen., n. sp. is unique among the Dasybatotreminae, by having: a well-developed, broadly ovoid anterior attachment organ with numerous grooves and an anteromedial notch; three prominent anterior glands that are connected to numerous peripheral glands; an unusual whip-shaped male copulatory organ composed of four connate tubes; an ejaculatory duct with slightly sclerotized walls where the proximal end has criss-crossed creases and the distal portion is highly convoluted; an ejaculatory bulb with one bipartite internal seminal vesicle; a wheel-shaped haptor with one central loculus and eight peripheral loculi; anchors that are much shorter than the width of marginal membrane and have an accessory sclerotized piece present; four oval testes, arranged in two groups; an ovary that has six clavate, proximal lobules and a distal portion that is strongly coiled; intestinal ceca with large lateral and medial diverticula; an oral opening surrounded by numerous small dome-like papillae; and a single vagina with sclerotized walls. Dasybatotreminae is amended to accommodate the new genus, and the new species is fully described and illustrated herein. The present finding adds to the other three marine monocotylids previously reported from Peru, namely Anoplocotyloides chorrillensis Luque Iannacone, 1991; Anoplocotyloides papillatus (Doran, 1953) Young, 1967 and Monocotyle luquei Chero, Cruces, Iannacone, Sanchez, Minaya, Saez Alvarino, 2016.
98 citations
TL;DR: The Monogenea is a group with a fairly well worked out taxonomy that has been investigated in regard to epidermal fine structure so that the cytoarchitecture of this layer is now known in most of the major groups.
Abstract: Publisher Summary This chapter discusses the epidermis and sense organs of Monogenea and their larvae and also with the epidermis of some Turbellaria and Aspidogastrea. Although Turbellaria contains free-living forms but they are considered in the chapter because their epidermal fine structure with its function and development is considered to be related particularly to the free-living stages of the larvae of monogeneans. In addition, study of the turbellarians as a whole adds considerably to the knowledge of the range of epidermal structure open to the Platyhelminthes allowing the constancy of epidermal cytomorphology in various groups. It's possible use in taxonomy to be assessed and fostering a dawning appreciation of plasticity upon a basic structural plan in conformation to functional requirement. The Monogenea is a group with a fairly well worked out taxonomy that has been investigated in regard to epidermal fine structure so that the cytoarchitecture of this layer is now known in most of the major groups. Regarding sense organs and nervous systems: the ranges of neurotransmitter types and neurosecretory material need more detailed characterization and the function of neurosecretory products linked with the biology of these worms. More accurate methods for mapping sense organs on marine adult and larval worms, perhaps utilizing specific staining of nerve endings and stereoscan investigations involving critical point drying to preserve ciliary endings, are called for. The electrophysiological response of accessible sense organs (e.g. the haptor papillae of entobdellids) also needs to be studied. In all cases these investigations should be closely related to the overall behavior and biology of the stage under consideration.
91 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 6 |
| 2020 | 8 |
| 2019 | 5 |
| 2018 | 5 |
| 2017 | 5 |
| 2016 | 7 |