Changes in the Visual Fields Associated With Web Reduction in the Spider Family Uloboridae

Librería: ConchBooks, Harxheim, AlemaniaConchBooks

Vendedor de 4 estrellas

Vendedor de AbeBooks desde el 1 de marzo de 2007

Condición: Usado

EUR 5,75

Envío por EUR 24,00 
Se envía de Alemania a Estados Unidos de America

Cantidad disponible: 1 disponible

Añadir al carrito
Devoluciones gratuitas de 30 días

Descripción del artículo del vendedor

When visual fields of the primitive orb-weaver, Waitkera waitkerensis, are reconstructed using measurements taken from intact lenses and cross and longitudinal sections of the prosoma, they show that this species has complete visual surveillance, but that none of the visual fields of its eight eyes overlap. The more advanced orb-weaver, Uloborus glomosus, also has eight eyes, but each eye has a greater visual angle, giving this species a complex pattern of overlapping visual fields. Uloborids that spin reduced webs are characterized by reduction or loss of the four anterior eyes and other carapace modifications necessary for them to effectively monitor and manipulate their reduced webs. The eyes of these uloborids have greater visual angles than those of orb-weavers, resulting primarily from perimetric expansion of their retinal hemispheres. Additionally, the axes of their visual fields are more ventrally directed due to greater dorsal than ventral retinal expansion and to ventral redirection of the entire eye. Consequently, even though the anterior lateral eyes of the triangle-weaver Hyptiotes cavatus lack retinae, the species' six functional eyes permit complete visual surveillance and exhibit visual overlap. The single-line-weaver, Miagrammopes animotus, has lost its four anterior eyes, and with them much of the anterior vision and all of the visual overlap found in the other species. However, changes similar to those of H. cavatus permit this species to retain most if its dorsal and ventral visual surveillance. Thus, ocular changes act in consort to maintain relatively complete visual surveillance in the face of eye loss and other major carapace modifications necessary for the operation of reduced webs. 14 pp., 4 figs, 3 tabs, gr. 8.…

N° de ref. del artículo W36101

Detalles bibliográficos

Título
Changes in the Visual Fields Associated With Web Reduction in the Spider Family Uloboridae
Autor
Opell, B. D. & Ware, A. D.
Año de publicación
1987

ConchBooks

Harxheim, Alemania

Vendedor de 4 estrellas

Vendedor de AbeBooks desde el 1 de marzo de 2007

Tarifas de envío de Alemania a Estados Unidos de America

ArtículoDe 25 a 45 días hábilesDe 8 a 14 días hábiles
Primer artículoEUR 24,00EUR 34,00
Los plazos de entrega los establecen los vendedores y varían según el transportista y la ubicación. Los pedidos que pasan por la aduana pueden sufrir retrasos y los compradores son responsables de los aranceles o tarifas asociadas. Los vendedores pueden ponerse en contacto con usted en relación con cargos adicionales para cubrir cualquier aumento en los costes de envío de los artículos.

Métodos de pago

  • Visa
  • Mastercard
  • American Express
  • Carte Bleue
  • Apple Pay
  • Google Pay
  • Cheque
  • Efectivo
  • Factura
  • Giro bancario
  • PayPal

Descripción de la tienda

Founded in 1985 we are specialized in worldwide literature on Mollusca and marine invertebrates. Our publishing house has meanwhile published approximately 60 titles on that field of interest. We have stocks of most available international books on Malacology and a huge amount of antiquarian literature, even of the latter most titles are only available once.

Especialidad

Weichtiere / Shells, Schnecken / Snails & Slugs, Muscheln / Bivalves, Tintenfische / Squids / Octopusses / Ammonites, Malacology, Conchology, Marine Biology