Caecosphaeroma is a troglodyticisopod genus in the family Sphaeromatidae found in caves of NE and SW France. The genus was split off from Monolistra by Adrien Dollfus in 1896; in both genera, the female carries about 10 fertilized eggs in its external marsupium (brood pouch); they are white in Monolistra but bluish-green in Caecosphaeroma.[1]C. burgundum is the most studied species.
Three examples; two rolled into balls. These individuals were found in the Nancy spéléodrome (an abandoned underground aqueduct in Villers-lès-Nancy, France).
They measure from 2–20 mm long. As cave dwellers, they have lost their vision, but remain sensitive to light, which they shun. They are capable of volvation (rolling themselves into a ball) to protect themselves, rest, or sleep. During copulation the male and female embrace takes the form of two concentric spheres.
Developmentedit
Larva remain in the marsupium about 12 months,[2] and the animals continue growing for several years, reaching a final length of 10–20 mm.
Evolutionedit
The marine ancestors of Caecosphaeroma are believed to have migrated up the course of rivers and adapted to a subterranean environment that was relatively stable; meanwhile the marine environment of their ancestors changed, so Caecosphaeroma continued to differentiate as a separate lineage.[3]
Volvation in C. burgundumedit
C. burgundum has evolved in ways to improve its ability to curl into a ball. The mandibular palps and antennae are able retract into two deep grooves of the face, and the posterior margin of pleotelson (the last body segment fused with the "tail") provides greater mechanical support for the head. Evolution of volvation is seen in other subterranean isopods, but only C. burgundum is able to roll up into a hermetic sphere without any outward projections, and thus "approaches perfection in volvation".[4]
Referencesedit
^Sket, Boris (1986). "Isopoda: Sphaeromatidae" (PDF). Ann. Univ. Saraviensis (3): 104–159. Retrieved April 22, 2020.
^Daum, J. (1954). "Zur Biologie einer Isopodenart unterirdischer Gewässer: Caecosphaerom (Vireia) burgundum Dollfus". Ann. Univ. Saraviensis. 3 (1): 104–159.
^Dollfus, Ad. & Viré, A. (1904) - « Sur quelques formes d'isopodes appartenant à la faune souterraine d'Europe », Annales des sciences naturelles. Zoologie et paléontologie, série 8 tome XX, Ed. Masson et Cie, Paris, p. 411-412
^Marvillet, C. (1976). "Les adaptations à la volvation du squelette externe de la tête chez Caecosphaeroma burgundum Dollfus, Crustacé Isopode des eaux souterraines". International Journal of Speleology. 8 (4): 331–358. doi:10.5038/1827-806X.8.4.3. Retrieved April 22, 2020. (Article has English abstract.)
caecosphaeroma, troglodytic, isopod, genus, family, sphaeromatidae, found, caves, france, genus, split, from, monolistra, adrien, dollfus, 1896, both, genera, female, carries, about, fertilized, eggs, external, marsupium, brood, pouch, they, white, monolistra,. Caecosphaeroma is a troglodytic isopod genus in the family Sphaeromatidae found in caves of NE and SW France The genus was split off from Monolistra by Adrien Dollfus in 1896 in both genera the female carries about 10 fertilized eggs in its external marsupium brood pouch they are white in Monolistra but bluish green in Caecosphaeroma 1 C burgundum is the most studied species Caecosphaeroma As a troglodytic genus Caecosphaeroma lacks eyes Scientific classification Domain Eukaryota Kingdom Animalia Phylum Arthropoda Class Malacostraca Superorder Peracarida Order Isopoda Family Sphaeromatidae Genus CaecosphaeromaDollfus 1896 Species C virei Dollfus 1896 C burgundum Dollfus 1898 Contents 1 Description 2 Development 3 Evolution 4 Volvation in C burgundum 5 ReferencesDescription edit nbsp Three examples two rolled into balls These individuals were found in the Nancy speleodrome an abandoned underground aqueduct in Villers les Nancy France They measure from 2 20 mm long As cave dwellers they have lost their vision but remain sensitive to light which they shun They are capable of volvation rolling themselves into a ball to protect themselves rest or sleep During copulation the male and female embrace takes the form of two concentric spheres Development editLarva remain in the marsupium about 12 months 2 and the animals continue growing for several years reaching a final length of 10 20 mm Evolution editThe marine ancestors of Caecosphaeroma are believed to have migrated up the course of rivers and adapted to a subterranean environment that was relatively stable meanwhile the marine environment of their ancestors changed so Caecosphaeroma continued to differentiate as a separate lineage 3 Volvation in C burgundum editC burgundum has evolved in ways to improve its ability to curl into a ball The mandibular palps and antennae are able retract into two deep grooves of the face and the posterior margin of pleotelson the last body segment fused with the tail provides greater mechanical support for the head Evolution of volvation is seen in other subterranean isopods but only C burgundum is able to roll up into a hermetic sphere without any outward projections and thus approaches perfection in volvation 4 References edit Sket Boris 1986 Isopoda Sphaeromatidae PDF Ann Univ Saraviensis 3 104 159 Retrieved April 22 2020 Daum J 1954 Zur Biologie einer Isopodenart unterirdischer Gewasser Caecosphaerom Vireia burgundum Dollfus Ann Univ Saraviensis 3 1 104 159 Dollfus Ad amp Vire A 1904 Sur quelques formes d isopodes appartenant a la faune souterraine d Europe Annales des sciences naturelles Zoologie et paleontologie serie 8 tome XX Ed Masson et Cie Paris p 411 412 Marvillet C 1976 Les adaptations a la volvation du squelette externe de la tete chez Caecosphaeroma burgundum Dollfus Crustace Isopode des eaux souterraines International Journal of Speleology 8 4 331 358 doi 10 5038 1827 806X 8 4 3 Retrieved April 22 2020 Article has English abstract Portal nbsp Arthropods Retrieved from https en wikipedia org w index php title Caecosphaeroma amp oldid 1190836199, wikipedia, wiki, book, books, library,
