The Cellar Spider (Holocnemus caudatus) is a small, delicate arachnid native to the Mediterranean. While often overshadowed by its more famous relative, the Marbled Cellar Spider (H. pluchei), it shares many of the fascinating "vibrating" behaviors typical of the Pholcidae family.
Body & Appearance: It features a yellowish-grey, elongated body with a characteristic dark longitudinal stripe on the underside. Its legs are exceptionally long and spindly, often featuring white and black rings at the joints.
Size: Males typically measure between 5–5.5 mm in body length.
Native Range: This species is primarily found in Spain and Sicily.
Unique Anatomy: The spinnerets (silk-producing organs) are situated in the middle of the abdomen rather than at the very tip, forming a conical protuberance.
Fascinating Behaviors
The "Vibrating" Defense: Like most cellar spiders, when disturbed, they may rapidly pulse their bodies, making their entire web shake. This creates a "blur" that confuses potential predators.
Maternal Care: Females are known to carry their egg sacs in their mouthparts (chelicerae) until they hatch. They often do not feed during this time to protect the brood.
