Terebella lapidaria

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Terebella lapidaria
Terebella lapidaria. A monograph of the British marine annelids (1922)

Terebella lapidaria . A monograph of the British marine annelids (1922)

Systematics
Subclass : Palpata
Order : Canalipalpata
Subordination : Terebellida
Family : Crested worms (Terebellidae)
Genre : Terebella
Type : Terebella lapidaria
Scientific name
Terebella lapidaria
Linnaeus , 1767
Terebella lapidaria . A monograph of the British marine annelids (1922)

Terebella lapidaria , German and the masonry bit is a marine annelid of the Mediterranean and northeast Atlantic Ocean from the genus Terebella in the polychaete - Family of Terebellidae , who as detritus lives in crevices and rock holes.

features

The rather short, firm, cone-shaped body of Terebella lapidaria , tapering towards the rear, but enlarged again at the end , reaches a length of 3 to 9 cm and a width of 3 to 5 mm with a number of 80 to 160 segments . The thorax is not very clearly demarcated and the dorsal capillary-shaped bristles are present as far as the rearmost segments of the abdomen. The prostomium has no lateral extensions and has eye spots.

As with other species of the genus Terebella , the transverse prostomium is connected to the dorsal surface of the upper lip, the lower part one like a thick crest, the distal part like a pedestal. Eight or more uniformly cylindrical buccal tentacles with an eyelash groove are located near the mouth . The peristomium is reduced to enlarged lips, a large, short, hood-like upper lip and a button- to pillow-shaped lower lip.

Like other species of the genus, the rock drill has a compact tentacle membrane. On the 2nd, 3rd and 4th segment there are two branched gills , with the 4th segment alone bearing gills and bristles at the same time . The parapodia are missing side lobes. From the 4th segment, the notopodia have bristles that are sawn distally along one edge. From the 5th segment, i.e. the 2nd bristle-bearing segment, hook-shaped bristles sit on the neuropodia , which sit in simple rows on the first 7 such segments, then in double rows and again in simple rows on the abdomen. The thorax consists of more than 20 bristle-bearing segments. The third segment to be Nephridial papillae present. Ventrally there are 12 to 13 whitish to violet rectangular tags, which get smaller towards the back, and an abdominal groove runs as a light line on the abdomen. The body is reddish brown to pink, the gills vivid red, the tentacles yellow to orange.

The coelom fluid of Terebella lapidaria contains numerous coelomocytes with hemoglobin , which give the animal its reddish color and in which large amounts of oxygen can be stored, so that the annelid can survive critical times during the ebb . Annelworm also has a closed blood vessel system in whose blood hemoglobin is dissolved directly in the plasma and through which the organs are supplied with oxygen and nutrients. According to studies by RMG Wells and RP Dales (1975), the affinity of the hemoglobin of the coelomocytes is significantly higher than that of the hemoglobin in the blood plasma.

From Terebella lapidaria are in nature only the thin cylindrical to see yellow tentacles that he sticks out from its rocky lair. Because of this, like related species of the genus Terebella, it is called "spaghetti worm ", while the term crested worms is used for the entire family of Terebellidae.

distribution

Terebella lapidaria is distributed in the Mediterranean Sea and the Eastern Atlantic Ocean along the coast of the Iberian Peninsula and France to the English Channel and the British coast near Plymouth .

It lives in crevices and holes in the rock in the intertidal zone, where it survives the low-oxygen times of the ebb by storing the oxygen in the hemoglobin.

Development cycle

Terebella lapidaria is separate sexes. Females and males release their gametes into the open sea water, where fertilization takes place. From the zygotes, yolk- rich, free-swimming trochophora larvae develop, which already have an apical ciliary sensory organ 12 to 36 hours after fertilization. Behind these are eye spots whose light- sensing cells show characteristic phenomena. After a few days, the larvae can be fed with unicellular algae such as the haptophyte Isochrysis galbana , which is commercially used as mussel food. Larvae kept in vitro from the coast near Roscoff as part of a dissertation (Kieselbach 2012) metamophore after 2 months to creep worms, but only a few larvae survived the laboratory conditions.

nutrition

Terebella lapidaria feeds on detritus and microorganisms, for which it searches the substrate surface - rocks or sand and silt in between - with its eyelash-covered tentacles. The food particles are held by the tentacles with the help of mucus, whereby muscle contraction in the tentacles forms a groove in the area where the cilia are located. By doing the eyelashes, the food is transported to the mouth in the eyelash groove, or by curving the tentacles it is brought directly to the mouth. The feeding mechanism has been extensively studied by R. Phillips Dales (1955) and Muriel F. Sutton (1957).

Systematics and taxonomy

Genus Terebella , from Sea and River-side Rambles in Victoria , between 1783 and 1788
A sketch by Terebella , from The genera vermium exemplified by various specimens of the animals contained in the orders of the Intestina et Mollusca Linnaei , circa 1860

Mårten Kähler (Martinus Kahler) was the first to describe in Uppsala 1754 in his Dissertatio de Crystallorum generatione "water polyps that eat stones", to which Carl von Linné referred when he in 1767 in the 12th edition of the Systema naturae the genus Terebella with the single species Terebella lapidaria described. Linnaeus chose the generic name after the Latin terebella "Bohrerchen" from terebra "Bohrer" and for the species the epithet lapidaria , "Stein-", hence the German name "Steinbohrer". It was originally found in the Mediterranean near Marseille . In 1788 Georg Heinrich Borowski gave Linnés' description in German translation in his non-profit natural history of the animal kingdom . The animals were found in “holes in the rocks in the sea”, which is why it was assumed “that they dig into the stones by means of a caustic material that softens the stone, but which is very doubtful by others.” The Linnaeus description was still there quite unspecific; so he characterized the genus as a “thread-like worm; at the top stands the mouth from which a quiver-like acorn, attached to a handle, protrudes; There are eight filaments around the mouth. ”Linné also states that the worm has a lot of hairs (capillaria plura). The only species described, Terebella lapidaria, was, according to Linnaeus' words in Borowski's translation, "similar to a water snake, the body conical, the tail thinner, eight filaments on the front of the body, and four on the mouth." Not.

Emil Edler von Marenzeller re- described the species Leprea lapidaria in 1884 on the basis of specimens from the Mediterranean Sea and the French Atlantic coast and interpreted them as the same species as Linnés Terebella lapidaria . The same name Leprea lapidaria was also used by H. Augener in 1918 for animals on the Atlantic coast of South West Africa , but this Leprea lapidaria is now regarded by WoRMS as a synonym for another Terebella species, namely Terebella schmardai Day, 1934 . Pierre Fauvel created a new description of Terebella lapidaria in his Faune de France in 1927 . In contrast to some other annelids, there is still no evidence that Terebella lapidaria can actually actively dig itself into the rock.

literature

Web links

Commons : Terebella lapidaria  - collection of images, videos and audio files

Individual evidence

  1. ↑ H. Augener (1918). Polychaeta. Contribution to the knowledge of the marine fauna of West Africa. 2 (2): 67-625, plates II-VII.
  2. ↑ Leprea (Terebella) lapidaria Augener, 1918. WoRMS , 2018. Accessed May 10, 2018.