juliforms

Juliforms are a major group of millipedes distinguished by a barrel-shaped, cylindrical body and a highly ringed appearance. They form the core of the clade Juliformia and include several orders, notably Julida, Spirobolida, and Spirostreptida. The name juliform derives from the genus Julus, which typifies this body form. Members typically have many body segments with two pairs of legs on most segments, giving them a compact, robust look and a slow, looping gait.

Morphology and anatomy common to juliforms include a hard exoskeleton, a relatively small head with antennae, and leg pairs that are short in proportion to body length. The body rings (tergites and pleurites) are distinctly annulated, contributing to a pronounced, segmented profile. Coloration ranges widely among species, but many are brown or black in hue.

Habitat and ecology: Juliforms are cosmopolitan and primarily inhabit moist environments. They are commonly found in leaf litter, soil, rotting wood, and other sheltered microhabitats in forests, grasslands, and gardens. They are detritivores, feeding on decaying plant matter and fungal growth, and play a role in nutrient cycling and soil structure.

Behavior and defense: When disturbed, many juliforms curl into a tight coil as a defensive posture. They also secrete defensive chemicals from specialized glands to deter predators.

Reproduction and development: Reproduction is sexual, with eggs laid in moist soil. Juveniles hatch as small, leg-bearing forms and molt to reach adult size, acquiring additional segments and legs as they grow. The juliform body plan is a stable, long-lived feature of this group within Diplopoda.