Skip to main content

Table 3 Compilation of features of the nervous system in representatives of different spiralian groups with previously proposed relationship to Lobatocerebrum riegeri n. sp

From: Detailed reconstruction of the nervous and muscular system of Lobatocerebridae with an evaluation of its annelid affinity

  

ANNELIDA

MOLLUSCA

NEMERTEA

GNATHOSTOMULIDA

PLATYHELMINTHES

XENACOELOMORPHA

  

LOBATOCERBRIDAE

SIPUNCULA

ORBINIIDAE

SOLENOGASTRES

CAUDOFOVEATA

GASTROPODA

PALAEONEMERTEA

ANOPLA

BURSOVAGINOIDEA

FILOSPERMOIDEA

CATENULIDA

NEMERTODERMATIDA

  

Lobatocerebrum riegeri n. sp.

Phascoliun strombus

Scoloplos armiger

Dorymenia sarsii

Chaeoderma japonicum

Helminthope psammibionta

Cephalothrix linearis

Procephalo-thrix linearis

Lineus viridens

Gnathostomula peregrina

Rastrognathia macrostoma

Pterognathia meixneri

Stenostomum leucops

Nemertoderma westbaldi

 

Location of the ventral nerve cords

Intraepithelial

Intraepithelial/subepidermal

Intraepithelial

Subepidermal

Subepidermal

Subepidermal

Subepidermal

Subepidermal

Subepidermal

Intraepithelial

Intraepithelial

Intraepithelial

? (mainly subepidermal)

Intraepithelia to subepidermal

BRAIN

Lobular structure

+

?

+

-

+

+

+

+

+

-

? (−)

-

-

-

Central neuropile

+

+

+

+

+

+

+

+

+

+

? (+)

+

+

- (only commissures formed)

Number of brain commissures

4

2

4

1

1

1

>2

>2

>2

1

? (1)

1

1

2 rings (dorsally connected)

NERVE CORDS OF THE CENTRAL NERVOUS SYSTEM

Number of posterior longitudinal nerve cords

1 pair + 1 median cord

1 pair

1 pair

2 pairs (+1 median cord)

2 pairs

2 pairs

1 pair

1 pair + 1 dorsal median + 1 ventral median cord

1 pair

1 pair

1 pair

1 pair

1 pair

- (thin fibres, but no cords)

Median posterior nerve cord

+

-

-

+

-

-

-

+

-

+ (just a short piece)

? (−)

-

-

-

Number of rostral longitudinal nerve cords

2–9

0

0

-

-

2 pairs

?

4

Approx. 8 pairs

-

?

>3 paired and 2 unpaired

-

-

GANGLIA AND COMMISSURES ALONG THE VENTRAL NERVE CORD

Total number of ganglia

2 pairs

>2

>2

>2

>2

>2

?

?

1 pair

1 pair

? (1 pair)

1 pair

?

?

Nonganglionated posterior commissures

>2

?

>2

>2

>2

>2

?

1

?

1

? (1)

1 (2)

?

-

Presence of a subpharyngeal ganglion

+

+

+

+

+

+

+

+

+

+

? (+)

+

+

-

PERIPHERAL NERVOUS SYSTEM

 

Grid of distinct longitudinal and circular nerves

Nerve plexus

Grid of pairwise arranged longitudinal and several circular nerves per segment

?

?

?

?

Intraepidermal plexus around the rhynchocoel

Subepidermal plexus, commissural plexus, stomatogastric plexus, proboscidial plexus

5 longitudinal nerves

6 longitudinal nerves

3 dorsal longitudinal nerves

?

?

References

 

This study

[57, 73, 74]

[75, 76]

[40, 41]

[40]

[43]

[42, 48]

[42]

[77]

[78]

[17, 79]

[17]

[46, 80]

[81, 82]

  1. Details of the brain, the ventral nervous system, the stomatogastric nervous system and the peripheral nervous system are given in an attempt to reveal common features or possible apomorphies in Lobatocerebridae. Presence of a character is labeled with +, absence with -, numbers and additional informations are given wherever possible. “?” indicates the lack of information in the references mentioned, while reinvestigations from this study (in the case of L. riegeri n. sp.) and assumptions based on additional references are included by putting the assessment in brackets (+) or (−). Only species with previously [8–12] or recently [7] suggested relationship to Lobatocerebridae were considered. Insufficient information in one species was supplemented with closely related species, based on the literature acknowledged in the reference-row
Back to article page

BMC Ecology and Evolution

ISSN: 2730-7182

Contact us