Cephalopoda

Budelmann, Bernd U.

doi:10.1002/9781444318777.ch50

Cited by 26 publications

(42 citation statements)

References 122 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Chaetigerous structures, although not named chaetae, are also found in other taxa, e.g., the Köl-liker's organs of incirrate octopods (Budelmann et al, 1997) and the hair-like structures or bristles found on the mantle lobe of brachiopods (Gustus and Cloney, 1972;James, 1997). Gustus and Cloney (1972), particularly, pointed out the remarkable resemblance between the bristles of brachiopod larvae and the chaetae of polychaetes.…”

Section: Chaetaementioning

confidence: 98%

Larval development of Myzostoma cirriferum (Myzostomida)

Eeckhaut

Fiévez

Müller

2003

Journal of Morphology

View full text Add to dashboard Cite

The larval development of Myzostoma cirriferum is described by means of SEM, TEM, and cLSM. It is similar to that of other myzostomids and includes three stages: the protrochophore, the trochophore, and the metatrochophore. The protrochophore is a ball-shaped larva present in culture from 18-48 h after egg laying. It has no internal organs and its body is made of three cell types: covering cells and ciliated cells that are external and surrounded by a cuticle, and resting cells that fill the blastocoel. The trochophore is a pear-shaped larva that develops 20-72 h after egg laying; the body includes the same three cell types as the previous stage. The metatrochophore is a pear-shaped larva that develops between 40 h and 14 days and is characterized by the presence of two bundles of four chaetae. When fully developed, the metatrochophore has a digestive system (made of a pharynx, an esophagus, and a blind digestive pouch), two pairs of protonephridia, and a nervous system composed of a supraesophageal ganglion, circumesophageal connectives, and dorsal and ventral nerves. Metamorphosis generally occurs 7 days after egg laying. At that time, the metatrochophore loses its chaetae and becomes pleated ventrally. This ultrastructural analysis suggests that chaetae and the five ventral longitudinal nerve cords of M. cirriferum metatrochophores are homologous structures to those observed in some polychaete trochophores. Coupled with recent phylogenetic analyses, where the Myzostomida are placed outside the Annelida, homologies between myzostomid and polychaete larvae support the view that a trochophore appeared early during the spiralian evolution.

show abstract

Section: Chaetaementioning

confidence: 98%

Larval development of Myzostoma cirriferum (Myzostomida)

Eeckhaut

Fiévez

Müller

2003

Journal of Morphology

View full text Add to dashboard Cite

show abstract

“…It has been described in detail for several species (Young, 1971;Boyle, 1986;Mangold, 1989;and Budelmann et al, 1997, for reviews), and parts of the giant nerve fibers, reflexes driven by sense organs, and short-and long-term memory systems have been used as model systems in biomedical research (e.g., Gilbert et al, 1990, Abbott et al, 1995. On the other hand, with the exception of the comprehensive study by Marquis (1989) of the octopus brain, surprisingly little is known about the embryonic development of the cephalopod nervous system (Marthy, 1987;Boletzky, 1989;Fioroni, 1990).…”

Section: Indexing Terms: Neuropil; Brain Formation; Giant Axon; Invermentioning

confidence: 99%

Embryonic and paralarval development of the central nervous system of the loliginid squid Sepioteuthis lessoniana

Shigeno

Tsuchiya

Segawa

2001

J of Comparative Neurology

View full text Add to dashboard Cite

The embryonic development of the central nervous system (CNS) in the oval squid Sepioteuthis lessoniana is described. It has three distinct phases: (1) The ganglionic accumulation phase: Ganglionic cell clusters develop by ingression, migration, and accumulation of neuroblasts. (2) The lobe differentiation phase: Ganglia differentiate into lobes. The phase is identified by the beginning of an axogenesis. During this phase, neuropils are first formed in the suboesophageal mass, then in the basal lobe system, and finally in the inferior frontal lobes and the superior frontal-vertical lobe systems. (3) The neuropil increment phase: After the shape of the lobes reached its typical form, neuropil growth occurs, specifically in the vertical lobe. The paralarval central nervous system (CNS) is characterized by neuronal gigantism of the giant fibers and some suboesophageal commissures and connectives. The neuropil formation in the CNS of S. lessoniana occurs somewhat earlier than in Octopus vulgaris, although the principal developmental plan is quite conservative among the other coleoids investigated. Some phylogenetic aspects are discussed based on the similarities in the morphologic organization of their brains.

show abstract

“…The comprehensive anatomical works by Young and his associates have revealed the basic design of the cephalopod nervous system (for reviews see, Young, 1971;Budelmann, 1995;Budelmann et al, 1997). The function of the cephalopod nervous system has been analyzed in many behavioral (Wells, 1978;Hanlon and Messenger, 1996) and electrophysiological (Gilbert et al, 1990;Abott et al, 1995) studies.…”

mentioning

confidence: 97%

Organization of the nervous system in the pygmy cuttlefish, Idiosepius paradoxus ortmann (Idiosepiidae, cephalopoda)

Shigeno

Yamamoto

2002

Journal of Morphology

View full text Add to dashboard Cite

The idiosepiid cuttlefish is a suitable organism for behavioral, genetic, and developmental studies. As morphological bases for these studies, organization of the nervous system was examined in Idiosepius paradoxus Ortmann, 1881, using Cajal's silver technique and immunohistochemical staining with anti-acetylated alpha-tubulin antibody. The nervous architecture is generally identical to that described in Sepia and Loligo, but some features characterize the idiosepiid nervous system. The olfactory system is highly developed in the optic tract region. The dorsolateral lobes show large neuropils, connected with each other by a novel well-fasciculated commissure. Each olfactory lobe is subdivided into two lobules. The neuropils of the anterior and the posterior chromatophore lobes are very poorly developed. Neuronal gigantism is not extensive in the brain; enlarged neuronal cells are visible only in the perikaryal layer of the posterior subesophageal mass. The giant nerve fiber system is of the Sepia type; the axons are not markedly thick and the first-order giant fibers do not fuse with each other at the chiasma. Three-dimensional images by whole-mount immunostaining clarified the innervation pattern in the peripheral nervous system in detail. Two commissural fibers link the left and right posterior funnel nerves ventrally and dorsally. The stellate commissure, which is absent in Sepia and Sepiola, connects the stellate ganglia with each other. A branch of the visceral nerve innervating the median pallial adductor muscle is characteristically thick. Tubulinergic reactivity of the cilia and axons reveals the presence of many ciliated cells giving off an axon toward brain nerves in the surface of the funnel, head integument, arm tips, and epidermal lines. Some of these features seem to reflect the inactive nekto-benthic life of the idiosepiid cuttlefish in the eelgrass bed.

show abstract

Cephalopoda

Cited by 26 publications

References 122 publications

Larval development of Myzostoma cirriferum (Myzostomida)

Larval development of Myzostoma cirriferum (Myzostomida)

Embryonic and paralarval development of the central nervous system of the loliginid squid Sepioteuthis lessoniana

Organization of the nervous system in the pygmy cuttlefish, Idiosepius paradoxus ortmann (Idiosepiidae, cephalopoda)

Contact Info

Product

Resources

About