Bugula neritina (Linnaeus, 1758) commonly know as Brown bryozoans are flexible bushy colonies of purplish-brown. They are distributed in seas worldwide except in the except sub Arctic and sub Antarctic regions (Bishop Museum 2002). The cosmopolitan distribution of the species appears to be due to shipping introductions. Bugula neritina colonies are typically found in harbours and embayments, intertidal to 5m, attached to any available hard substrate (Bishop Museum 2002). Its branching is biserial, to about 10 cm high.

Nudibranchs have been recorded as consumers of Bugula neritina (NIMPIS 2002). Southern California studies have shown a high mortality rate for bryozoans during red tides (algal blooms). Bryozoans are preyed upon by grazing organisms such as sea urchins and fish. They are also subject to competition and overgrowth from sponges, algae, and tunicates (PWSRCAC 2004).
Bryozoans provide habitat for many species of juvenile fish and their invertebrate prey such as polychaete worms, amphipods and copepods (SMSFP 2001 in Winston 1995). Bryozoans are also found in association with other species that act as support structures: mangrove roots, oyster beds, mussels, etc. (SMSFP 2001).
The feeding activities of bryozoans and other filter feeding animals strain out excess food and debris particles to help keep the water clean (VMNH 2005). Bryozoan colonies located in 1m2 of seagrass bed could potentially filter and recirculate an average of 48,000 gallons of seawater per day (SMSFP 2001 in Winston 1995).

Bugula neritina colonies are the source of a novel chemical compound (bryostatin) which has been shown to be effective against leukaemia and a number of other kinds of cancer. A newly described species of bacterium, which is symbiotic to B. neritina cryptic species 'type D', appears to be the source of bryostatins (Davidson and Haygood, 1999; Davidson et al. 2001).

The first collection of Bugula neritina from the Gulf of Mexico in 1968 led to the isolation of bryostatin. The highest yielding source reported so far produced 15 mg bryostatin 10 out of 1.5 kg wet animal (1.0×10^-3% wt) and originated from the Gulf of Aomori in Japan The yield of the extraction is not only dependent on the geographical site, it also depends on the time of year and depths of the collection. Bryozoans collected from different sites also showed different bryostatin ratios

Bryostatins were also found in smaller quantities in the marine organisms Lissodendoryx isodictyalis, Aplidium californium and Amathia convoluta. Each organism was discovered to have Bugula neritina growing within its biomass. Whether these bryostatins are produced by the organism or transferred from Bugula neritina remains uncertain. In the case of Lissodendoryx isodictyalis, two novel bryostatins (A+B) were found. Full characterisation was not possible because of the small amounts obtained but there is evidence that they are desoxybryostatin 5 and desoxybryostatin 4 respectively. It is thought that they may be formed as metabolites by the organismwhilst neristatin 1 is a possible biosynthetic precursor or degradation product obtained from Bugula neritina, in combination with low toxicity, has made this class of compounds a chemotherapeutic candidate for the treatment of cancer. The specific interactions with protein kinase C (PKC), and other enzymes, led to a wide range of studies directed towards a better understanding of its specific activity as well as clarifying the mechanism of action of cellular signalling pathways in general. The limited supply and the low concentration in the natural source yielded an investigation of the marine animal and attempts to cultivate it. The unique chemical structure of the bryostatins posed a major synthetic challenge