First Description of an Encrusting Bryozoan Hippopodina iririkiensis Artificial Settlement Collectors Deployed in Colombo Port, Sri Lanka

Abstract

attached

Bryozoans are aquatic organisms mainly occur in marine environments. Some bryozoans considered as nuisance species since they foul on ship hulls, pilings, pier, docks and water intake pipes. Conversely, there are certain bryozoans that produce chemical compounds which have beneficial medical properties. Furthermore, present study revealed many bryozoan species which have a significant impact on the ecology of the biofouling community settled in artificial collectors in Colombo port. However, there are number of species which remains mysterious to Sri Lanka and present study aims to put such species under scrutiny. Biofouling samples were collected from six sampling locations within Colombo port using artificial settlement collectors. These collectors were deployed in four different depths where the first set was 1 m below the water surface and others setting at 1 m intervals. Monthly samples were collected from October 2014 to August 2017. Specimens were identified morphologically using fine morphological features and samples were quantitatively assessed by determining their covering percentage and species abundance. Present study recorded eight encrusting bryozoans from Colombo port including Hippopodina iririkiensis. H. iririkiensis belongs to class Gymnolaemata, order Cheilostomatida, suborder Flustrina and family Hippopodinidae. This species was recorded from Unity Container Terminal (UCT) at 4m depth with a covering percentage of 5.75. The colony is encrusting, multiserial, unilamellar and often large in size. Autozooids are generally rectangular and separated by distinct grooves. The frontal wall is convex and evenly perforated with small pores. The primary orifice is hoof shaped and rounded distally; wider than the proximal margin which is slightly concave. Two prominent lateral condyles were present and an operculum which closes the orifice. Adventitious avicularia are often paired; occasionally, single or absent, placed distolaterally to the orifice. Ovicell is large and evenly perforated. H. iririkiensis is widely distributed throughout the Indo-West Pacific region. However, their status within the country is not yet confirmed.