The study of algal diversity from fresh water bodies of Chimmony Wildlife Sanctuary, Kerala, India

: The algal diversity of the freshwater ecosystem is very significant because they are the primary energy producers in the food web. The study for the algal diversity was conducted at Chimmony Wildlife Sanctuary, Thrissur, Kerala, India, from selected sampling sites (Pookoyil thodu, Kidakkapara thodu, Viraku thodu, Nellipara thodu, Anaporu thodu, Kodakallu thodu, Odan thodu, Mullapara thodu, Payampara thodu, Chimmony dam). The identified algal species belong to four different classes: Chlorophyceae, Euglenineae, Rhodophyceae, and Cyanophyceae. Sixty-one algal species were identified, represented by 37 genera, 22 families, and 14 orders. Among the four, Chlorophyceae was the dominant class.


INTRODUCTION
Algae are the most abundant aquatic organisms present in the freshwater ecosystem. Algae were responsible for the beginning of multicellular life on our planet and could be the key to our future survival. They are an essential source for producing fine chemicals, natural pigments, vitamins, polysaccharides, bioflocculants, and growth promoters. Algae are also a significant producers of oxygen than plants (Rai et al. 2000).
The freshwater ecosystems are mainly categorized into two types: lotic and lentic. The rivers, streams, waterfalls, canals fall into the lotic type, and the stagnant waters like pools, lakes, reservoirs and paddy fields fall into the lentic type. The freshwater algal diversity varies from unicellular phytoplankton to colonial and much larger multicellular algae. The algal biodiversity depends upon the physicochemical parameters of the water bodies. In the food chain of aquatic ecosystems, algae are the primary producers, making them very important. So the conservation and knowledge about algal biodiversity are necessary for maintaining a healthy aquatic ecosystem.
The information regarding species diversity is an essential component to realize life in its fullness and conserve it for future generations (Pandey 1995). Therefore, there is a strong demand for research on biodiversity in developing countries (Briji 2005;Tessy & Sreekumar 2017). Generally, the taxonomy is considered an outdated science that cannot keep up with the present biodiversity crisis (De Clerck et al. 2013). But for the future development in biodiversity research, systematics and taxonomy are important (Koen & Segers 2005).
The study of biodiversity as the present one opens new opportunities to understand the different algal forms in their respective natural habitat. The large algal species in the freshwater ecosystem depict its diversity. In the current scenario, hardly a few genera are used in the industry, giving a broad scope for other potential obtainable algae. Even though plenty of literature is available on fresh water algal diversity of Kerala, there is no published record available on the algal diversity of Chimmony Wildlife Sanctuary. Hence the study.

Study area
The study was conducted in Chimmony Wildlife Sanctuary (CWS; Figure 1), which is situated in the Thrissur District of Kerala state. It belongs to Mukundapuram taluk and within geographical limits of 10.40° & 10.48° E and 76.41° & 76.56° N. CWS has an area extent of 85.067 km 2 and water spread area of 10.1 km 2 . The sanctuary consists of more than 250 streams, which drains into the Chimmony Reservoir (George 2012; Velayudhan et al.  2021). In this study, 10 different streams were selected to study the algal flora (Table 1).

RESULTS
In the study conducted in CWS, 61 algal species were recorded, which belongs to four different classes (Chlorophyceae, Euglenineae, Rhodophyceae, and Cyanophyceae). These species are represented by 37 genera, 22 families, and 14 orders ( Table 2). The class Chlorophyceae represents 33 taxa under 22 genera, the class Euglenineae represents seven taxa under four genera, the class Rhodophyceae represents one taxa under one genera, and the class Cyanophyceae represents 20 taxa under 10 genera.

Class: Chlorophyceae
Order: Volvocales Family: Chlamydomonadaceae Genus: Chlamydomonas Ehrenberg 1. Chlamydomonas globosa Snow (Image 1) Prescott, 1961, p.71, pl.1, figs. 8,9 The cells are globose, enclosed in a hyaline, gelatinous sheath. The cell is 3-5 μm in diameter and 5-10 μm long. The cell consists of a parietal cup-shaped chloroplast with basal pyrenoid and a contractile vacuole at the anterior end. The cell is covered with a smooth membrane and two flagella at the anterior end. The pigment spot is small and inconspicuous.
Family: Volvocaceae Genus: Gonium Mueller 2. Gonium pectorale Mueller (Image 2) Prescott, 1961, p. 75, pl.1, fig. 22 The colony consists of 16 ellipsoid to subspherical cells arranged in a flat quadrangular plate. This quadrangular plate consists of four inner cells covered by 12 marginal cells. The anterior ends of marginal cells were projecting outwards. Each cell is enclosed in an individual sheath and the cells are 5-20 μm in diameter.
Chlorococcum humicola (Naeg.) Rabenhorst (Image 4,5) Prescott, 1961, p. 212, pl.45, fig. 1 The colony is unicellular, non-motile, with spherical cells in various small clumps. Each cells consist of a completely filled spherical chloroplast with a single pyrenoid. The cell is 7-10 μm in diameter.   The cell is straight and fusiform, having a tapering from the centre towards the pointed ends. The cell is 45-50 μm long and 2-3 μm broad.

Monoraphidium indicum Hindak (Image 7)
Hindak , 1977, p.105, pl.44 The cells are very thin and are accurately curved. The cell has a tapering towards the end and it is pointed. The cell is 40-45 μm long and 1.5-2 μm broad. The cells are rusty-brown in colour sometimes the thallus shows yellow colour in shaded regions. The cells are slightly swollen but slightly reduced in diameter towards apices. The cell has a smooth wall, and it is 4-10  fig. 160 The filaments are greenish and unbranched. The cells are rectangular to square in shape. Presence of two star-shaped chloroplasts. The cell is 11-15 μm long and 10 μm broad. The scalariform conjugation results in the formation of globose shaped zygospore in the tube. The globose zygospore is formed at the right angle of the tube, and it measures 13-16 μm in length and 15-20 μm in breadth.

J TT
The plant is 5-9 cm high and has a highly mucilaginous thallus, which is brown to green. The central axes are 90-105 μm wide, and glomeruli are ellipsoidal to globular. The lateral branches have short internodes. The carpogonia are 4-5 μm wide at the basal portion and 25-30 μm long. The trichogyne are elongate, club-shaped and embrace the carpogonia. The carposporophyte is globular and scattered close to the periphery. The carposporophyte measures 14-150 μm in diameter.

Genus: Cylindrospermum
Family: Rivulariaceae Genus: Gloeotrichia Ag. 58. Gloeotrichia echinulata (J. E. Smith) P. Richter (Image 75, 76) Prescott, 1962, p.557, pl. 134, figs. 1,2 The colonies are tiny macroscopic and opaque at the centre and translucent at the periphery. The colonies are free-floating, spherical and covered in a gelatinous sheath. The trichomes radiate from a common centre and are tapered from basal heterocyst to a fine hair-like end. The cells are cylindrical to barrel-shaped 6-9 μm wide, and the cells are joined end to end to form long chains.

DISCUSSION
The freshwater ecosystem holds the most biodiversity among all other ecosystem. The study of freshwater habitat is significant as it occupies only 0.5% of the earth surface, but is equally crucial because they are the cheapest natural source for domestic and industrial purposes (Norton et al. 1996).
The present study portraits the algal diversity of CWS. In our study, Chlorophyceae and Cyanophyceae algae were dominant. The preliminary study conducted in Kannam River, Kannur, Kerala for the diversity of algae has reported 40 algal species of which Chlorophyceae was dominant, followed by Cyanophycea (Girish et al. 2018). The algal population of Pennar River, Kottayam, has reported 61 algal species were Chlorophyceae was dominant (Joseph & Claramma 2010). In our study also, more algae were reported from the order Zygnematales, and Spirogyra was the most common genus. The algal species from order Nostocales of Cyanophyceae was dominant. A similar type of diversity was observed in the Gundur lake of Tamil Nadu. Out of 87 algal species reported from Gundur Lake, 37 species were Cyanophyta (Vijayan et al. 2014). The algae from Chlorophyceae and www.threatenedtaxa.org The Journal of Threatened Taxa (JoTT) is dedicated to building evidence for conservation globally by publishing peer-reviewed articles online every month at a reasonably rapid rate at www.threatenedtaxa.org. All articles published in JoTT are registered under Creative Commons Attribution 4.0 International License unless otherwise mentioned. JoTT allows allows unrestricted use, reproduction, and distribution of articles in any medium by providing adequate credit to the author(s) and the source of publication.