An assessment of bryozoan ( Phylactolaemata ) fauna of Kagzipura Lake , Aurangabad , Maharashtra , India

Material and Methods Attempts were made to collect the colonies and statoblasts in fortnightly sampling from May 2010 to April 2013. Material was collected from the Kagzipura reservoir (19058’16”N & 75012’31”E) situated 40km northwest of Aurangabad City (Image 1). Bolten silk (No. 25) 40mm mesh plankton net was used for sampling the free floating statoblasts. Colony samples were also collected from the submerged surface or the underside of floating objects like plants, wood, rocks, plastics, etc. Both samples were taken to the laboratory in separate polythene bags. Colonies were examined under stereozoom dissecting microscope. Some statoblasts were stored in the aquarium for germination study while the remaining were stored in 70% alcohol for SEM analysis. The preserved statoblasts were cleaned with 0.1N sodium hexametaphosphate by shaking vigorously to remove debris attached on statoblast (Wood An assessment of bryozoan (Phylactolaemata) fauna of Kagzipura Lake, Aurangabad, Maharashtra, India

Bryozoans are sessile invertebrates that grow as colonies of identical zooids attached to submerged objects like rocks, macrophytes, metal plates, molluscan shells, even plastic pipes and plastic bags.Within the phylum Bryozoa, class Phylactolaemata live exclusively in freshwater habitats.The phylactolaemates comprises five families (Massard & Geimer 2008).Bryozoan taxonomy is complex and depends largely on microscopic details.Colony morphology and statoblast morphology are used for the identification.Scanning electron microscopy (SEM) photographs are used to describe the surface feature of statoblasts (Wood & Lore 2005).In India, Nelson Annandale was the pioneer of bryozoan studies while Kotapali Rao provided an excellent work 2001).Species were identified using keys described by Annandale (1911), Lacourt (1968), Rao (1992), and Wood (2006Wood ( , 2010)).

Results
In the present study four bryozoan species are recorded, namely Rumarcanella vorstmani Toriumi, 1952 (Image 2), Swarupella divina Wood, 2006 (Image 3), Plumatella casmiana Oka, 1907 (Image 4) and Lophopodella carteri Hyatt, 1968 (Image 5).Rumarcanella vorstmani floatoblasts are nearly symmetrical laterally, small and short with sides briefly parallel near the centre and the ends broadly rounded, both fenestrae bear small tubercles with hypertubercles, they have irregular annulues.Colony composed of slender branches, which attach to the substratum throughout their length.
Swarupella divina floatoblast is broadly oval with substantial annulues on both sides; fenestra has roughly the same proportions as the entire floatoblast.Swarupella divina is identified on the basis of statoblast only; the colonial form was not collected or identified during the survey.
Plumatella casmiana having capsulated statoblast is a typical plumatellid statoblast with a central capsule surrounded by periblast, dorsal and ventral fenestrae are narrowly oval and elongate but never round, both fenestrae are faintly tuberculated.Colony is usually compact and neat, the tubules short richly branched and lying flat along the substratum.
Lophopodella carteri statoblast is oval and flattened at each end and possesses a series of hooked spines on both extremities which is broadly rounded, the longest spines being in the middle and the shortest at the ends of the series.The colony is gelatinous and firm, colony wall is soft and transparent.Polypide has an elongated horseshoe shaped lophophore.Colonial form (with well developed lophophores) of Lophopodella carteri observed only once in May 2013.The statoblast measurements (length and breadth of overall statoblast and annulus) of all four species are given in Table 2.

Discussion and Conclusion
Indian studies are restricted to West Bengal and Madhya Pradesh states because Annandale was the first Director of Zoological Survey of India, Kolkata (West Bengal) while Rao's workplace was in Ujjain (Madhya Pradesh).Among the four species reported here, two species (Plumatella casmiana, Lophopodella carteri) are also previously recorded by us from Mula dam and from central and northern India (Rao 1992).
The two species Swarupella divina and Plumatella vorstmani are reported for the first time from this region.Rumarcanella vorstmani was first described in 1929 from Indonesia by Adriana Vorstman as Plumatella javanica; P. vorstmani was recently placed in a new genus, Rumarcanella (Hirose & Mawatari 2011).
Swarupella divina was described from a single colony collected at Bung Borophet in Thailand.The proportions of the floatoblast and its fenestrae are very similar to those in Rumarcanella vorstmani but the floatoblast in Swarupella divina is about 20% larger overall (Wood et al. 2010).The identification of Swarupella divina is confirmed by Prof. Timorthy Wood on the basis of statoblast morphology and dimensions.This is the first report on the occurrence of Swarupella divina (statoblast) from India.None of the species encountered in this study is endemic to the region and wide distributions of the species are possibly related to the dispersability of floatoblasts by birds or other living organisms (Hirose & Mawatari 2007).The species discovered in this region has been serendipitous and many undescribed species are likely to exist.Much of western and southern India  is still unexplored for bryozoans so the probability of encountering additional new species remains high; and we are optimistic that even more species will eventually be revealed in this region.