The beautiful Hypselodoris (Hypselodoris pulchella) is a golden nudibranch, a marine gastropod mollusk. They are commonly seen on the reefs of Tanzania, usually, but not always, with one individual after another. The smaller individual follows the larger individual.

APPEARANCE

The ground color of the dorsal area is Ƅlanco, with indistinct purple lines that form random patterns throughout the body. A large number of yellow spots of different sizes cover the dorsal area. The mantle edge and foot each have a distinct solid purple line around the edge. The rhinopores are purple-blue in color and are made up of approximately 30 roughly semicircular plates on each side of the supporting arm. These can be seen in the image below. These plates contain chemoreceptors and maximize surface area. These chemoreceptors are used to detect small amounts of trace chemicals in seawater and are used to detect food sources and proƄaƄlemently to find other individuals for tracking and mating purposes.

The gills are located in the posterior part of the body and are not fixed, but move with the currents. They are flank in color with purple Ƅordes.

When threatened, the gills can be retracted into the body as shown below.

IN NATURE

Hypselodoris pulchella is common during the day in Tanzanian waters. They are usually crawling with a specimen closely following the foot of the specimen in front. There seems to be no explanation for the tracking. With all ease, it allows the larger specimen to find food sources and the smaller specimen to follow the benefits, since it uses less effort to do so. Whether there is any other advantage to this type of behavior is open to speculation. One could speculate that an ʋeʋolutiʋa advantage is gained by staying close to a potential mate, since they are hermaphrodites. This proximity then facilitates mating and facilitates mating to occur. In this way, the need to search for a partner is dispensed with and, in theory, tracking is more efficient.

HABITAT

Hypselodoris pulchella is found in the Indian Ocean and the western Pacific. They have been found in mixed areas of rubble and coral in Tanzania at depths of 12 metres.

DIET

The Bellos Hypselodoris feed mainly on certain species of sponges. They insert a tube into the sponge and emit fluids that partially digest it. This partially digested food is then absorbed by the body for further digestion.

REPRODUCTION

They are simultaneous hermaphrodites and mating is done by connecting the dual organs that are located on the right side of the body. Once the two organs connect, the sperm is transferred to each specimen. The eggs are laid on a solid substrate in a ribbon and when hatched, the larae ʋfollowʋplanktonic before becoming adults. The whorls of the bones are reddish.

HYPSELODORIS PULCHELLA CLASSIFICATION Kingdom: AnIMalia Phylum: Mollusca Class: Clade Gastropods Heterobranchia Euthyneura Nudipleura Nudibranchia Superfamilia: Doridoidea Familia: Chroмodorididae Genus: Hypselodoris Species: Hypselodoris pulchella LITERATURE CITED The Reef Guide Fishes, corals, nudibranchs and others in south-eastern coasts and others Africa by Dennis King and Valda Fraser EQUIPMENT USED Ikelite 7D Housing Ikelite Canon 7D Strobe Arm Ikelite Strobe Light Ikelite Lens Port Flat Ikelite Dual Sync Cable Ikelite 5.1 Inch Port Body