PYCNOGONOIDEA Patricia Nicole M. Perez BSBIO3A Mrs. Virginio

Pycnogonidea or Pantopoda (sea-spiders) are a group of marine arthropods.

Kingdom: Animalia Phylum: Arthropoda Subphylum: Chelicerata Class: Pycnogonida

Anatomy of a pycnogonida : A. head; B. thorax; C. abdomen 1. proboscis; 2.chelifores; 3. palps; 4.ovigers; 5. egg sacs; 6a–6d : four pairs of legs

Characteristics The body is slender, segmented, and divided into two regions, the head and the trunk. The head features a number of pairs of appendages, including two pairs of feeding appendages (chelifores) with pincers at the tips, a proboscis with the mouth at the end, and both sexes have a pair of egg-carrying 'legs‘.

The trunk bears four pairs of long, spindly legs, and has a small projection at the rear called the abdomen

There are more 1300 species of pycnogonids described and it is believed there are many more species to be discovered mainly from remote deep-sea habitats. The known species are traditionally distributed in 80 genera and eight or nine families as they are: Ammotheidae, Austrodecidae, Callipallenidae, Colossendeidae, Nymphonidae, Phoxichilidiidae, Pycnogonidae, Rhynchothoracidae, and Endeididae a monogeneric family sometimes included in Phoxichilidiidae.

Habitat Sea spiders usually live near the shore. They are found crawling over seaweeds as well as on sea anemones, small sea animals with long, thin, armlike body parts called tentacles corals, the hard skeletons of certain sea creatures; and other animal colonies, or tight groupings of animals, permanently attached to the sea bottom. Some species are found at great depths, up to 23,000 feet (7,000 meters), where they live near hot water springs bubbling up from the sea floor.

Location They are cosmopolitan, found especially in the Mediterranean and Caribbean Seas, as well as the Arctic and Antarctic Oceans. There are over 1300 known species, ranging in size from 1 to 10 millimetres (0.039 to 0.39 in) to over 90 cm (35 in) in some deep water species.

Life Cycle Pycnogonids do not have a planktonic stage in their life cycle, and this is believed to have implications for the patterns of distribution and a possible high rate of speciation. In species of callipallenids and nymphonids the larvae stay attached to the parent's ovigers until they reach a well-developed stage (after the fourth instar) (Nakamura 1981). Pycnogonid protonymphs resemble a nauplius larva of the crustaceans, but they have a proboscis, bear chelifores with strong pincers, and have two other pairs of appendages with a single terminal claw. There is little information to date on morphological characters of larvae and juvenile stages.

Examples Nymphon gracile Kingdom:Animalia Phylum:Arthropoda Class:Pycogonida Order:Pantopoda Family:Nymphonidae Genus:Nymphon

Scientific Name: Nymphon gracile Location: Hitra, Norway Has a smooth body up to 1 cm long. Body length up to 10 mm.

Pycnogonum stearnsi Kingdom: Animalia Phylum: Arthropoda Class: Pycnogonida Order:Pantopoda Family: Pycnogonidae Genus: Pycnogonum Species:Pycnogonum stearnsi

Scientific Name: Pycnogonum stearnsi Location: Fitzgerald Marine Reserve, Moss Beach, California, USA Description color white to pale yellowish-white. Proboscis barrel- shaped, without bumps or swellings. Legs relatively short, without tubercles. Size: Typically about 5mm in length; leg span up to about 10mm.

Anoplodactylus evansi Kingdom: Phylum: Animalia Arthropoda Class:Pycnogonida Family:Phoxichilidiidae Genus:Anoplodactylus Species:Evansi

Habitat: Red algae in rock pools and on subtidal reef, to depth of 16 m. Identifying Characters: Body mainly red, with blue markings. Yellow around the leg joints. Body up to 1 cm long.