INVERTEBRATE ZOOLOGY - H. I. Shcherbak - 2008

KINGDOM MULTICELLULAR ANIMALS (METAZOA)

SUBKINGDOM EUMETAZOA

DIVISION TRIPLOBLASTICA, OR BILATERAL ANIMALS (BILATERIA)

SUBDIVISION ECDYSOZOA

PHYLUM ARTHROPODA

SUBPHYLUM TRACHEATA

SUPERCLASS MYRIAPODA

CLASS PAUROPODA

This is the least studied group of myriapods. They remained practically unknown until the mid-19th century, although it turned out that pauropods are widely distributed in both the Old and New Worlds. Around 400 species have been described.

They inhabit the upper layers of forest soils, living under stones, in compost, and in rotting wood. Some species are synanthropic. Pauropods can be called miniature myriapods: the smallest barely reach 1 mm, while the largest do not exceed 1.9 mm.

Morphology. The body is typically elongated in shape (Fig. 353). The HEAD segments are not completely fused; the last (cervical) segment remains free and lacks appendages. Unlike other myriapods, the antennae in pauropods are branched. Eyes are absent. The head bears a pair of stout, serrated mandibles and a single pair of maxillae. The trunk consists of 10-12 segments, of which the first, or sometimes two to three, lack appendages. The number of tergites is smaller than the number of segments, indicating a partial pairwise fusion of segments. There are five pairs of long sensory hairs on the sides of the body.

A notable feature of the Digestive System is the presence of well-developed Muscles surrounding the anterior ectodermal region. This suggests that pauropods feed by suction. Specifically, species such as Pauropus lanceolatus and Allopauropus gracilis are known to suck out the hyphae of mold Fungi. In addition, pauropods include both saprophages and predators.

Excretory Organs are represented by a pair of Malpighian tubules.

The Circulatory system is absent.

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Fig. 353. Pauropods

(from Ghilarov): a - Pauropus chuxleyr, b - Eurypauropus ornatus

The Respiratory system has a simple Structure: short pairs of tracheal tubes extend from spiracles located at the Base of the legs.

Reproductive System. The Gonads of females and males differ in structure: the Ovary is unpaired, whereas There are two pairs of Testes. The genital openings are paired and open at the base of the second pair of legs.

Reproduction. Pauropods lay eggs, which hatch into larvae with three pairs of legs. The number of trunk segments increases after each molt (anamorphosis). Adult pauropods do not molt.

A typical representative of pauropods is Pauropus sylvaticus, a species widely distributed in Europe.