Middorsal

Definition

Situated at or along the dorsal midline of the body; pertaining to the central axis of the dorsal (upper) surface. In arthropods, this term specifies structures positioned medially on the tergites or carapace, as opposed to subdorsal (lateral to the midline) or dorsolateral positions.

Etymology

From Latin medius (middle) + dorsalis (of the back)

Example

In a grasshopper, the middorsal region of the pronotum often bears a distinct longitudinal carina or ridge, while the subdorsal areas carry the lateral lobes.

Synonyms

• mediodorsal

Related Terms

• Dorsal
• Subdorsal
• dorsolateral
• ventromedial
• midventral
• tergite
• carina

Usage Notes

Middorsal contrasts with subdorsal (immediately lateral to the dorsal midline) and dorsolateral (more broadly on the dorsal-ventral junction). In insect morphology, 'middorsal' is preferred over 'mediodorsal' in North American usage, though both appear in literature. The term is absolute, not relative to body segments—use 'proximal middorsal' or 'distal middorsal' if segmental position must be specified. In spiders, 'middorsal' commonly describes setal patterns or color markings centered on the carapace or opisthosoma.