Olavius ​​algarvensis

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Olavius ​​algarvensis
Olavius ​​algarvensis from Elba, Italy

Olavius ​​algarvensis from Elba, Italy

Systematics
Trunk : Annelids (Annelida)
Class : Belt worms (Clitellata)
Order : Little bristle (Oligochaeta)
Family : Tubificidae
Genre : Olavius
Type : Olavius ​​algarvensis
Scientific name
Olavius ​​algarvensis
Giere et al., 1998

Olavius ​​algarvensis is a species of belt worms (Clitellata) from the order of the little bristle (Oligochaeta). The worm, 12 to 25 millimeters long, lives on the Portuguese Atlantic coast and in the Italian Mediterranean in the subtidal coastal sand. Like all species of the genus Olavius, it does not have a digestive tract and operates its metabolism via symbiotic bacteria. Olavius algarvensis was 1998 by Olav Passengers , Christer Erséus and Frank Stuhlmacher first described .

features

O. algarvensis is 12-25 mm long and has 100-150 segments. Like all other species of the genus Olavius , the species has no digestive tract. The genital segment XI is around 0.27 mm wide, the width of the postgenital segments is 0.25-0.27 mm. Since the body surface is very irregular, the width of the rest of the body varies. The prostomium is elongated and measures around 100  µm . The clitellar glands are relatively strong and extend from half of the X. to the XII. Genital segment. On the abdomen in the XIV. Genital segment there is a large subcutaneous pad made of symbiotic bacteria, from which two grooves, also filled with bacteria, extend to the XII. Genital segment extend where they enclose the female pores. The penile bristles of O. algarvensis are around 70 µm long and are in bundles of ten to eleven. They are 2.5–3 µm thick and are covered by the male papillae. In each bristle bundle, the front bristles are longer than the rear ones. The spermathecal pores are arranged in pairs and are located between the genital segments IX and X and the rear bundle of bristles. 

The cuticle and epidermis are often in direct contact with one another. Because the length of the strands of the epidermis is different, the thickness of the epidermis also varies. There are also numerous glandular cells between the epidermal cells. The sperm funnel is 42 µm wide and 15 µm deep. The spermatic duct has a length of 125 µm, is 10 µm wide and is not muscled. The narrow, 80–100 20 µm measuring atrium of O. algarvensis is narrow and is almost perpendicular to the body axis. The anterior prostate is lobed and large, 11 µm long and 70–90 µm wide. The posterior prostate is vertical and 95 µm long and 55 µm wide. The length of the spermatheque is 130 µm, they are about 40 µm wide. 

distribution and habitat

Olavius ​​algarvensis was first discovered in a lagoon on Portugal's Algarve coast . The species was later discovered on the coast of the Italian island of Elba . It lives in coarse-grained, subtidal sand with 0.8–1.1% debris . The water depth of the habitat is up to one meter off Portugal, but depths of 10–15 cm are preferred, off Italy the species was found in 10–18 cm depth. The local water temperature in the Algarve is up to 30 ° C, the salt content is 35.5–37 ‰. In front of Elba the temperatures are 26 ° C in summer and a minimum of 13 ° C in winter, the salinity in summer is 37 ‰. 

Way of life

Olavius ​​algarvensis , in the absence of a digestive tract , carries out its metabolism with the help of bacteria with which the species lives in symbiosis . These living in the skin of the worm bacteria oxidize carbon monoxide to aerobischem and anaerobic way, including through the reduction of sulfates . The electrons obtained from this can be used for energy in subsequent reactions with a large number of elements and chemical compounds. In addition, the bacteria apparently use hydrogen (H 2 ) from the anaerobic CO oxidation as an energy source. O. algarvensis itself produces acetates , malates and succinates as metabolic products as well as urea and glycine betaine . The latter two are in turn used by the symbiotic bacteria, which is an important source of nitrogen in the species' habitat . 

The bacteria living symbiotically with O. algarvensis are a delta-proteobacterium that produces numerous proteins containing selenoproteins and pyrrolysin. Selenocysteine and pyrrolysine are considered the 21st and 22nd amino acids . This bacterium, which lives in a symbiotic manner in O. algarvensis, has the largest known selenoprotein and pyrroproteome to date due to the use of almost 100 selenoproteins.

Systematics

Olavius ​​algarvensis was discovered off the coast of Portugal in the 1990s and was first described in 1998 by Olav Giere, Christer Erséus and Frank Stuhlmacher . The species was the first member of the genus to be found in European waters; all previously known Olavius species came from the Caribbean . Giere and colleagues chose the specific epithet algarvensis based on the place where it was found, the Algarve . The relationships between the species are unclear, Giere and Erséus assume that the Atlantic and the Mediterranean were colonized by Olavius species from the Caribbean. There are clear differences between the two populations off Portugal and Elba, for example in the number of symbionts, their location and the size of the worms. The two scientists therefore suspect a gradual settlement first of the Atlantic coast and then of the Mediterranean Sea, whereby the species adapted to the different habitats in different ways and the additional symbionts off Elba only acquired later. 

swell

literature

Individual evidence

  1. ↑ a b Giere et al. 1998, pp. 210-213.
  2. ↑ Giere & Erséus 2002, pp. 292–293.
  3. ↑ a b Giere & Erséus 2002, p. 293.
  4. ↑ Giere et al. 1998, pp. 212-213.
  5. ↑ Kleiner et al. 2012, pp. 2–9.
  6. ↑ Y. Zhang, VN Gladyshev: High content of proteins containing 21st and 22nd amino acids, selenocysteine ​​and pyrrolysine, in a symbiotic deltaproteobacterium of gutless worm Olavius ​​algarvensis. In: Nucleic acids research . Volume 35, Number 15, 2007, pp. 4952-4963, ISSN  1362-4962 . doi : 10.1093 / nar / gkm514 . PMID 17626042 . PMC 1976440 (free full text)
  7. ↑ Giere & Erséus 2002, pp. 295–296.

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