An endogenous circadian hatching rhythm in the monogenean skin parasite Entobdella soleae, and its relationship to the activity rhythm of the host (Solea solea).

نویسنده

  • G C Kearn
چکیده

1. When the eggs of the skin parasitic monogenean Entobdella soleae are subjected in the laboratory to alternating periods of light and darkness (LD 12:12, LD 6:18 or LD 18:6) at constant temperature (selected from the range 12-16 °C), hatching is rhythmical, most of the oncomiracidia emerging during the first 4 h of the period of illumination on each successive day. 2. Rhythmicity in response to alternating 12 h periods of light and darkness persists in a wide range of lighting conditions including natural daylight and in dim blue light, the latter being similar in intensity (65 nW/cm) and in spectral quality to light at the depths where the host Solea solea lives. 3. The hatching rhythm persists with a periodicity of about 24 h in constant darkness and in constant light, provided that the eggs have been exposed previously to LD 12:12 until hatching begins. This indicates that there is a strong endogenous component to the rhythm. 4. Eggs laid and maintained in total darkness develop and hatch, but the oncomiracidia may emerge at any time during each 24 h period and there is little evidence of rhythmicity. 5. When alternate 12 h periods of light and [darkness are reversed after the commencement of hatching, the hatching pattern also reverses after 24 h, so that emergence of larvae occurs at the beginning of the new illumination period. 6. Mechanical disturbance plays little or no part as a hatching stimulus. 7. Larvae, which had emerged from their eggs at some time between 20 and 80 min previously, responded to host skin, suggesting that an initial uninfective period is of short duration or absent. 8. Hatching soon after dawn may have high survival value for E. soleae in view of the host's activity pattern; soles are active at night and partly bury themselves in the sediment (where the eggs of the parasite lie) at dawn, and the fish is inactive and a stationary target during the day.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Some Aspects of the Biology of Monogenean (Platyhelminth) Parasites of Marine and Freshwater Fishes

Müller [1] was the first to describe a monogenean, collected from the skin of the halibut (Hippoglossus hippoglossus). However, he regarded the parasite as a leech and named it Hirudo hippoglossi. It was not until 1858 that its status as a monogenean was established by van Beneden [2] and named Epibdella (now Entobdella) hippoglossi. Van Beneden published a detailed and accurate description of ...

متن کامل

Effect of an Antagonist of Vasoactive Intestinal Polypeptide on Biological Rhythm of Rest Activity in the Rat

Abstract Vasoactive Intestinal Polypeptide (VIP), has been found in different neurotransmitter systems and exists in various nerve tracts in the brain. Potential role of this peptide in physiological processes such as regulation of sleep and wakefulness, and biological rhythms has been confirmed in several reports. In the present research effects of intracerebroventricular (ICV) injection of a...

متن کامل

Effect of Circadian Rhythm on Antiulcer Activity of Hydroxyzine in Cold Stress Induced Ulcer in Wistar Albino Rats

Circadian rhythms are driven by endogenous clock gene and affects in several gastric parameters causing ulcerogenesis. The study was aimed to evaluate the time dependent antiulcer activity of hydroxyzine in cold-stress-induced ulcer model. The ulcer protection effect of hydroxyzine was studied at various time intervals (9 am, 1 pm, 5 pm, 91 pm, 1 am and 5 am) in cold stress ulcer model using wi...

متن کامل

Effects of Circadian Rhythm on Physical and physiological Performance of Military forces- Narrative Review

The 2017 Nobel Prize for medicine was awarded the biological clock Scientist, which shows the importance of this phenomenon in the life of living organisms. The circadian Rhythm (CR) through the created internal “clock” is responsible for regulating the daily performance of different organs of the body. The central body clock is the key factor to creating and maintaining this CR. External optic...

متن کامل

Sub-tegumental ventral fibres surrounding the vaginal opening of Entobdella soleae (van Beneden et Hesse, 1864) Johnston, 1929 (Platyhelminthes: Monogenea: Capsalidae).

The distribution of F-actin in the monogenean Entobdella soleae (van Beneden et Hesse, 1864) Johnston, 1929 (Platyhelminthes: Capsalidae) was revealed by staining paraformaldehyde-fixed specimens with FITC-labelled phalloidin. On the ventral surface on the left side of the body, just posterior to the pharynx, a concentrically arranged array of fluorescent fibres was observed, following a circul...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Parasitology

دوره 66 1  شماره 

صفحات  -

تاریخ انتشار 1973