Eledone gaucha
| Eledone gaucha | ||||||||||||
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| Eledone gaucha | ||||||||||||
| Haimovici , 1988 |
Eledone gaucha is a small cephalopod from the family of the real octopus (Octopodidae). It lives on the coast of Brazil . The species was first described by Manuel Haimovici in 1988.
etymology
The name "gaucha" is derived from the coastal plains of southern Brazil, Argentina and Uruguay and their people.
features
anatomy
Eledone gaucha has a mantle length of 65 millimeters, with the females being slightly smaller.
The mantle has an elongated and egg-shaped shape. The skin is not particularly thick. A separation can be seen between the coat and the narrowing of the head. The head is narrower than the coat. The eyes protrude slightly.
Eledone gaucha has a well-developed throat, with the anterior salivary glands being smaller than the posterior. The esophagus is connected to a well-developed goiter and leads to the muscular abdomen. The small, spiral-shaped appendix is united with the large digestive gland by two passages. The intestine is relatively thin and leads to the ink pouch adjacent to the anus. The surface of the ink bag is embedded in the digestive gland. The funnel organ is long and W-shaped and the front half is exposed. The radula has a large, three-pointed central tooth, called the rachis , three posterior teeth and a rim plate. The gills are divided into 7–10 external hemispheres . Hemibranches are gills that only have lamellae on one side. There are eight most common in males, while nine in females.
The velar skin runs deep and reaches down to more than half the arm's length. It is less deep between the dorsal and ventral pairs of arms. Eledone gaucha has a single row of suction cups on each tentacle . These are small, of even size, clearly separated from each other and reach deep down to the head. In females, the suction cups on the tips of the tentacles appear to be cluttered. Male animals have tentacles in different shapes, with the third right arm forming the hectocotylus . The ligula is small and has no differentiated calm. At the tips of the non-hectocotyledonous arms the suckers end in two rows of fleshy papillae or lamellae.
Appearance
The color of living animals varies: some are uniformly brown, others almost pure white in the dorsal area and colorless on the ventral side. The body surface is smooth. However, there are wart-like structures called papillae on the back of the mantle and head. There are also two rows of tiny papillae on each of the non-hectocotyledon arms.
Animals soaked in alcohol turn purple-gray on the back and light yellow on the ventral side.
Like all real octopuses, Eledone gaucha can adapt its appearance to its surroundings. This camouflage is based on a combination of different chromatophores and a change in the texture of the skin. There are fewer chromatophores on the inner surface of the tentacles, mouth, and ventral mantle than on the rest of the body.
Way of life
nutrition
Eledone gaucha feeds on small fish, crabs , lobster-like and molluscs .
habitat
The species has so far only been found on the coasts of the Brazilian state of Rio Grande do Sul between Solidão and Chuí . Eledone gaucha lives at a depth between 52 and 140 meters below sea level.
Reproduction
The males have a long, tubular penis with a very short diverticulum , with which the males form clusters of sperm, so-called spermatophores . These are transmitted to the female with a special tentacle, the hectocotylus . The number of spermatophores is undifferentiated. In samples from 40 sexually mature males, they differed in number between 7 and 92. The females have a long, proximal fallopian tube with small fallopian glands. The distal fallopian tube is a bit shorter and thicker. The eggs in the ovary are oval. The mature egg cells have a maximum length of eight millimeters. In studies of 42 female animals, 10–55 eggs developed.
Individual evidence
- ↑ a b c Cephalopods of the world. An annotated and illustrated catalog of cephalopod species known to date (p. 121)
- ↑ a b c d e f g h i j Manuel Haimovici: Eledone gaucha, a new species of eledonid octopod (Cephalopoda: Octopodidae) from southern Brazil (1988)
- ↑ Skin as superreflectors
- ↑ Octopodidae - Article at Tree of Life