The Small World of Freshwater Gastrotrichs
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  • Body short, bottle-shaped
  • Cephalion present
  • behind setola on papillae
  • 1-3 pairs of ventrolaterally antspringing, strong spur spines
  • posterior spines protrude the trunk by up to one body length
  • further dorsal jumping spines
  • no secondary spines
  • ventral cilia in rows, no tufts
  • jumping movements for escape possible due to jumping spines

6 Species:

Haltidytes crassus

200 µm - 209 µm
Dorsal scales: No scales; 5 pairs of non-crossing elastic spines projecting above the body; two spines each starting ventrally
Ventral scales: no scales; 3 pairs of long jump spines (100 - 240 mm); posterior ones overhang the body by one body length and cross each other
Particularities: Setae stand on clear papillae

Haltidytes festinans

120 µm - 122 µm
Dorsal scales: no scales; dorsolaterally 3 groups each of 3 + 2 + 2 jump spines, which protrude even in resting position and slightly overhang the body
Ventral scales: no scales; a pair of long jumping spines (140-144 µm), surpassing the body by 3/4 of its length and crossing each other

Haltidytes ooeides

Haltidytes pseudosquamosus

Haltidytes saltitans

83 µm - 85 µm
Dorsal scales: no scales; two long, straight caudal spines (70-75 µm); 4 pairs of dorsolateral crossing spines
Ventral scales: no scales; one pair of long, crossing hock spines (80-82 µm)
Particularities: inadequately described

Haltidytes squamosus