MURRAYIDAE Guidetti, Rebecchi & Bertolani, 2000

Pilato, Giovanni & Binda, Maria Grazia, 2010, Definition of families, subfamilies, genera and subgenera of the Eutardigrada, and keys to their identification, Zootaxa 2404, pp. 1-54 : 44

MURRAYIDAE Guidetti, Rebecchi & Bertolani, 2000

Eutardigrades without cephalic papillae. Epicuticular layer not compact due to the presence of pillar-like structures ( Fig. 25 A). The two diploclaws of each leg, similar in shape and size to each other, are symmetrically arranged with respect to the median plane of the leg (conventionally described as: 2112). The diploclaws have the two branches diverging immediately after a short common basal section ( Fig. 25 B,C,D). In all known genera the buccal tube is rigid and asymmetrical with respect to the frontal plane due to the presence of a ventral lamina ( Fig. 25 E). Ten peribuccal lamellae are present in all the known genera with the sagittal plane passing through the medio-dorsal lamella and the medio-ventral one ( Fig. 2 ); peribuccal papulae absent.

Types of claws. Three types of claws are known within the family.

1) The Murrayon type (= pullari type) ( Fig. 25 B)

The basal section of the diploclaw is a trapezoidal lamina ( Bertolani & Pilato, 1988). The primary and the secondary branches are joined to each other for a very short portion and form an acute angle (V shaped claws).

2) The Dactylobiotus type (= macronyx type) ( Fig. 25 C)

The basal section of the diploclaw is a trapezoidal lamina ( Bertolani & Pilato, 1988). The secondary branch is clearly shorter than the primary branch and inserted near the base of the latter. The two branches form an almost right angle ( Guidetti et al., 2000 defined this type of claws as “L-shaped claws”).

3) The Macroversum type ( Fig. 25 D)

The basal section of the diploclaw is subdivided into a thin, flexible, stem and a distal portion that is not very sclerotised ( Pilato & Catanzaro, 1988). The primary and the secondary branches are connected to each other for a short portion and form an almost right angle ( Guidetti et al., 2000 defined this type of claws as “Lshaped claws”).

Figures

FIGURE 2. Scheme of bucco-pharyngeal apparatus of Macrobiotus (Macrobiotidae). cp = caudal processes; pha = pharyngal apophyses; pl = peribuccal lamellae; pla = placoids; sp = sagittal plane; st = stylet; stf = stylet furcae; sts = stylet support; stsh = stylet sheaths; vl = ventral lamina.

FIGURE 25. Pillar-like structures of the cuticle; claws and bucco-pharyngeal apparatus of Murrayidae. A, cuticle; B, claws of Murrayon; C, claws of Dactylobiotus; D, claws of Macroversum; E, bucco-pharyngeal apparatus of Murrayon (variant of the Macrobiotus type). (B, C, from Bertolani & Pilato, 1988; D, from Pilato & Catanzaro, 1988).