ZOO115 Invertebrate Zoology Phylum Onychophora

Onychophora (Talon bearer)- General Characteristics Common name: Velvet worms Intermediate between annelids and arthropods ~110 species Fossil records from Early Cambrian period (~530 MYA) Terrestrial Dark humid tropical regions http://www.mnhn.fr/assoc/myriapoda/IMAGES/OOPERIHI.JPG

Onychophora - General Characteristics Soft-bodied Wormlike 5mm-15cm in length Segmented with serial repetition of organs http://www.cals.ncsu.edu/course/zo150/mozley/fall/Onychophora.jpg

Onychophora – Support Body is covered by thin chitinous cuticle Similar to arthropods Highly permeable Flexible Accordion-like Longitudinal, circular, diagonal and surface oblique muscles Body wall, other than cuticle, similar to Annelids Circular/Diagonal muscle Longitudinal muscle Hemocoel Slime gland Oblique muscle Attached to surface

Onychophora - Locomotion http://www.jcu.edu.au/school/tbiol/zoology/pictures/peripat5.jpg Trunk bears 13-43 pairs of appendages with claws Like parapodia of polychaetes Operated as part of the hemocoel http://www.jcu.edu.au/school/tbiol/zoology/pictures/peripat2.jpg

Onychophora - Nutrition Carnivores - eat small arthropods Secrete jets of slime up to 30 cm to entangle prey Lacerate prey with mandibles (jaws) Secrete saliva with hydrolytic enzymes Pharynx pumps liquid food into stomach http://www.cals.ncsu.edu/course/zo150/mozley/fall/Onychophanat.jpg

Onychophora - Digestion Chitin-lined foregut (pharynx and esophagus midgut (intestine – digestion and absorption Slime gland http://www.cals.ncsu.edu/course/zo150/mozley/fall/Onychophanat.jpg

Onychophora - Excretion Anus for solid waste Nephridia - like arthropods http://www.cals.ncsu.edu/course/zo150/mozley/fall/Onychophanat.jpg

Onychophora – Circulation Open system similar to arthropods tubular heart with pericardial sinus large hemocoel Gas exchange small openings in each segment– Spiracles lead to tracheal tubes Heart From Brusca and Brusca (2003) Hemocoel Nephridia

Onychophora - Nervous system Ladderlike nervous system - like both annelids and arthropods Paired ventral nerve cord Sensory Antennae Eyes at base of antennae Sensilla on sensory papillae http://www.cals.ncsu.edu/course/zo150/mozley/fall/Onychophanat.jpg

Onychophora - Reproduction Separate sexes Sexually dimorphic Males smaller Sperm transferred by spermatophore In Peripatopsis, spermataphores placed anywhere on female, her cuticle temporarily dissolves and takes up the sperm. Most bear live young