Salt and Water Regulation in Macrobdella Decora (Hirudinea: Gnathobdelliformes) Under Osmotic Stress

1987 ◽  
Vol 131 (1) ◽  
pp. 337-349
Author(s):  
ANGELA WENNING
Keyword(s):  
Medicinal Leech ◽  
Central Canal ◽  
Urine Flow ◽  
Water Regulation ◽  
Transport Capacity ◽  
Artificial Blood ◽  
The North ◽  
Macrobdella Decora ◽  
External Salinity ◽  
Blood Meals

The anatomy, infrastructure and innervation of the nephridia of the North American leech, Macrobdella decora (Say), are described. The osmotic concentrations of blood, crop fluid and final urine, as well as urine flow under normal conditions, were found to be similar to those of the well-studied European medicinal leech, Hirudo medicinalis L. The capacity of the excretory system after changes in external salinity, and after salt and water loading with artificial blood meals, was investigated. In contrast to H. medicinalis, M. decora does not tolerate hypertonic environments and is less efficient in rapidly excreting excess salt and water. Three factors make salt and water regulation in M. decora different from that in H. medicinalis: a slower fluid resorption from the crop, a limited transport capacity of the primary urine-forming cells, and a lower rate of salt reabsorption in the central canal. Note: Dedicated to Professor Dr Ernst Florey on the occasion of his 60th birthday.

scholarly journals Salivary Transcriptome of the North American Medicinal Leech, Macrobdella decora

2010 ◽  
Vol 96 (6) ◽  
pp. 1211-1221 ◽  
Author(s):  
Gi-Sik Min ◽  
Indra Neil Sarkar ◽  
Mark E. Siddall
Keyword(s):  
North American ◽  
Medicinal Leech ◽  
The North ◽  
Macrobdella Decora

Twelve variable microsatellite loci for the North American medicinal leech, Macrobdella decora

2004 ◽  
Vol 4 (3) ◽  
pp. 491-493 ◽  
Author(s):  
REBECCA B. BUDINOFF ◽  
AIMEE M. SIDDALL ◽  
MARK E. SIDDALL
Keyword(s):  
North American ◽  
Microsatellite Loci ◽  
Medicinal Leech ◽  
The North ◽  
Macrobdella Decora

scholarly journals Novel Role for Aeromonas jandaei as a Digestive Tract Symbiont of the North American Medicinal Leech

2006 ◽  
Vol 73 (2) ◽  
pp. 655-658 ◽  
Author(s):  
Mark E. Siddall ◽  
Paul L. Worthen ◽  
Matthew Johnson ◽  
Joerg Graf
Keyword(s):  
Digestive Tract ◽  
Dna Sequences ◽  
North American ◽  
Geographic Area ◽  
Medicinal Leech ◽  
Gut Bacteria ◽  
Biochemical Tests ◽  
The North ◽  
Macrobdella Decora

ABSTRACT The gut bacteria of the North American medicinal leech, Macrobdella decora, were characterized. Biochemical tests and DNA sequences indicated that Aeromonas jandaei is the dominant culturable symbiont in leeches from a broad geographic area. In this work we identified a new habitat for A. jandaei, and here we suggest that there is unexpected specificity between leeches and Aeromonas species.

The distribution of putative neurosecretory cells in the central nervous system of the North American medicinal leech Macrobdella decora

1979 ◽  
Vol 57 (10) ◽  
pp. 1905-1914 ◽  
Author(s):  
Rodney A. Webb ◽  
I. Orchard
Keyword(s):  
Ventral Nerve Cord ◽  
Medicinal Leech ◽  
Neurosecretory Cells ◽  
Nerve Cells ◽  
Dense Granules ◽  
The North ◽  
Macrobdella Decora ◽  
Cell Groups ◽  
The Central Nervous System ◽  
Neurohemal Organs

Nerve cells that displayed a distinct Tyndall blue–white effect were observed in the supra- and sub-oesophageal ganglia, the ventral nerve cord ganglia, and the posterior ganglion of the Gnathobdellid leech Macrobdella decora. These cells formed four anatomically distinct groups in the supraoesophageal ganglion and occupied characteristic and analogous positions in the other ganglia. Light microscopy of these blue–white cells revealed histochemical properties not seen in other nerve cells. The perikarya of the four groups of blue–white cells in the supraoesophageal ganglion were examined with the electron microscope and found to contain large membrane-bounded electron-dense granules similar to those observed in proven neurosecretory cells. Tracts from two of these cell groups possibly form primitive neurohemal organs. A neurosecretory role for the blue–white cells is suggested.

scholarly journals Exploring the attachment of the Mediterranean medicinal leech ( Hirudo verbana ) to porous substrates

2020 ◽  
Vol 17 (168) ◽  
pp. 20200300
Author(s):  
Tim Kampowski ◽  
Lara-Louise Thiemann ◽  
Lukas Kürner ◽  
Thomas Speck ◽  
Simon Poppinga
Keyword(s):  
High Speed ◽  
Medicinal Leech ◽  
Mechanical Tests ◽  
Artificial Substrates ◽  
Hirudo Verbana ◽  
The Mediterranean ◽  
The Rich ◽  
Attachment Mechanism ◽  
Blood Meals ◽  
Porous Substrates

Haematophagous ectoparasites must ensure a reliable hold to their host during blood meals and, therefore, have evolved a broad spectrum of versatile and effective attachment mechanisms. The Mediterranean medicinal leech ( Hirudo verbana ), for example, uses suction on both smooth and textured air-tight substrates. However, preliminary studies showed that H. verbana is also capable of attaching itself to air-permeable substrates, where suction does not work. Using high-speed videography and mechanical tests, we comparatively investigated the attachment of H. verbana on both smooth and textured air-tight as well as on porous artificial substrates, also considering the influence of mucus on sucker surfaces. In general, the leech-specific locomotion cycle did not differ between the tested surfaces, and the leeches were able to reliably attach to both air-tight and porous substrates. From our results, we conclude that suction is presumably the primary attachment mechanism of H. verbana . However, secondary mechanisms such as mechanical interlocking with surface asperities and pores or capillary forces occurring at the interface between the mucus-covered suckers and the substratum are also employed. In any case, the rich repertoire of applicable attachment principles renders the organs of H. verbana functionally highly resilient.

scholarly journals Ingestive behaviour and physiology of the medicinal leech

1988 ◽  
Vol 137 (1) ◽  
pp. 513-527 ◽  
Author(s):  
C. M. Lent ◽  
K. H. Fliegner ◽  
E. Freedman ◽  
M. H. Dickinson
Keyword(s):  
Body Wall ◽  
Initial Rate ◽  
Medicinal Leech ◽  
The Body ◽  
Meal Size ◽  
Blood Sucking ◽  
Animal Size ◽  
Ingestive Behaviour ◽  
Blood Meals ◽  
Blood Meal Size

Ingestion lasts 25 min in Hirudo medicinalis and is characterized by pharyngeal peristalsis which fills the crop. This peristalsis has an initial rate of 2.4 Hz which decays smoothly to 1.2 Hz at termination of ingestion. During ingestion, the leech body wall undergoes peristalsis which appears to aid in filling the crop diverticula. Body peristalsis begins at a rate of 10 min-1 and decreases linearly to 2 min-1 at termination. The body also undergoes dorsoventral flexions when blood flow is occluded. Blood meal size increases slightly with leech size: 8.4 g for 1-g leeches and 9.7 g for 2-g leeches. However, relative meal size decreases markedly with increasing animal size; from 8.15 times body mass for 1-g to 4.80 times for 2-g leeches. When intact leeches were exposed to micromolar concentrations of serotonin, there was an increase in the rate of pharyngeal peristalsis and the size of the blood meals. Leeches excrete the plasma from their ingested blood meals. Excretion is activated during ingestion, which increases feeding efficiency by increasing the proportion of blood cells in the ingestate. Excretion continues for 4–6 days following ingestion, removing all the remaining plasma from the ingestate. Leech ingestion comprises stereotyped muscular movements, secretion of saliva and excretion of plasma. A strikingly similar feeding physiology is seen in the blood-sucking insect Rhodnius, and we suggest that efficient sanguivory may require the convergent evolution of similar ingestive mechanisms.

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