Family: Pholcidae
Subfamily: Holocneminae
Genus: Crossopriza
Species: Crossopriza lyoni
♀5mm

♂7.5mm

EDA SAWMILL 21-11-2014 FRI 8:46AM

CONTAINER 28-11-2014 FRI 8:32AM

|  MALE  |  FEMALE  |

Crossopriza lyoni

The carapace (the top part of the cephalothorax) has a deep excavation.

Pholcids are long-legged spiders which construct loose tangled webs. Some of them are responsible for the "cobwebs" at neglected corners of buildings. They hang upside down in the webs and when disturbed, will vibrate themselves so vigorously that they blur themselves in the eyes of the intruder.

 The jaws are fused at the base. Under a microscope, ring-like impressions are discernible on the long and apparently flexible tarsi (the last segment of the leg)

Crossopriza lyoni is a widespread species of cellar spiders that prefer to live in or around human structures. They are commonly known as tailed cellar spiders, tailed daddy longlegs spiders, and sometimes box spiders. They all possess extremely long fragile legs that can reach up to 6 cm (2.4 in) long and a body length of that ranges from 2.5 to 7 mm (0.098 to 0.276 in). Their abdomens are distinctly squarish when viewed from the side and their carapace is more or less circular when viewed from above. They also possess two kinds of sound-producing organs and have six eyes.

The original range of C. lyoni is unknown. They have been introduced into other parts of the world accidentally and are now pantropical in distribution. They are a regulated species in some countries and are often regarded as pests due to the large amounts of unsightly webs they construct inside human homes. Some people, however, regard them as beneficial, as they are efficient predators of mosquitoes and other arthropods. They are harmless to humans.

They also possess two types of stridulatory organs. The first type is located at the posterior tips of their cephalothorax (the prosoma) in the form of two triangular protrusions. The spiders rub these structures with a matching pair of sclerotized plates at the anterior portion of the abdomen, producing sound. These structures are more prominent in females. They also possess stridulatory files (in the form of a series of small ridges) on their chelicerae which are rubbed against the pedipalps to produce sound. The second type is more prominent in males.

 

Eggs of  Crossopriza lyoni

The eggs are deposited by the females 5–6 days after copulation. 5 to 54 spiderlings will eventually hatch from the eggs, 11 to 13 days after egg-laying.

Each egg diameter is less then 1mm and is round like a pearl.

After laying the eggs, females will bind them into a ball with tiny amounts of silk. They then clutch the resulting egg sacs with their mouthparts and carry them around.

Eggs are held together by a few strands of silk and carried by the mother.
Due to too much movement of the female spiders during photographing, half of her eggs fell off from the sac. (above image). Eggs that somehow fall from the loose bundles do not hatch.

The females still feed during this period, setting their burdens aside temporarily while they eat, then picking them up again. They also frequently adjust their grip. Instances of females eating some of their own eggs have been recorded. It is assumed that they only consume the infertile ones, as unfertilized eggs occur at high enough rates

EYES

They have eight eyes located in the tip of cephalothorax. The anterior median pair is small while the rest are set in two groups of three.

In the middle of the upper surface (the carapace) is a deep depression (thoracic fovea) and a darker longitudinal band of color.

Cephalothorax
Cephalothorax wider than long, greyish white in colour, a dark band along mid longitudinal line; top part of the cephalothorax with deep excavation. Legs long, fragile, with fine hairs; small black spots all over the legs, joints are black in colour.
 

Pedipalps
Male Crossopriza lyoni spiders are recognizable by the enlarged pedipalps. 

Male bulbous pedipalps
Female slender pedipalps

Carapace = The hard dorsal covering of the cephalothorax.
 

The cephalothorax is wider than it is long, greyish-white to pale amber in color.

The carapace is subcircular. In the middle of the upper surface is a deep depression (thoracic fovea) and a darker longitudinal band of color.

A small conical hump projected at the upper posterior end of the abdomen.
 

Abdomen

Abdomen is greyish off white with black and white patches in the sides and dorsum; cardiac area transparent; triangular in shape when viewed from sides, with the spinnerets located in the lower projection of the triangle. A small conical extension is projected at the upper posterior end of the abdomen.

The 'knee joints' are brown, and the ends of the femur and tibiae are girdled with white.

Females have slightly shorter legs than males.

Males are slightly smaller, at about 2.5 to 6 mm (0.098 to 0.236 in) in length, and have prominent pedipalps.

1- 6 eyes Crossopriza lyoni
2- 8 eyes Crossopriza lyoni

The Crossopriza lyoni found in Borneo Island are 8 eyes.

The eyes are pearly-white in color and located at the tip of the cephalothorax in two groups of three.
 

The characteristic boxy shape of their abdomens (C. cylindrogaster has a cylindrical abdomen)

The abdomen (the opisthosoma) is gray with white lateral stripes and various dark and light patches on the sides and the upper surface. An irregular darker stripe runs lengthwise at the bottom surface. The abdomen is angular and somewhat box-shaped, with a small conical hump on the upper back.

SPIDERS OF BORNEO