Abstract: The present study was carried out an marine ornamental invertebrate`s resources of Parangipettai coastal waters during the month of March-August 2006, which revealed the occurrence of 28 species of marine ornamental invertebrates belonging to 4 phyla. From this the species diversity was high during the month of April and May and it was decreased in March. The most abundant species recorded during the study period was fiddler crab Uca annulipes, while sea star Ludia maculata was very least in their abundance.
INTRODUCTION
India is consecrated with a rich biodiversity and a high degree of endemism in hot spot areas (Anna Mercy, 2002). India has a long coastline of about 8129 km with varieties of commercially important marine ornamental fishes. The Gulf of Mannar, Gulf of Kutch, Andaman, Nicobar and Lakshadweep Islands are very potential areas with highly valuable marine ornamental fishery resources for the collection and utilization. The marine fish and invertebrate resources from the Andaman and Nicobar Islands and Lakshadweep are reported to be the richest in Asia. More than 500 species of invertebrates are available in these islands (Ramachandran, 2002).
In recent years, researchers, traders, collectors and hobbyist have began a world wide effort minimize the growing pressure on natural populations of marine ornamental species and to promote the sustainable use of these highly valued resources (Corbin, 2001). The tropical species of the genus Lysmata, Periclimenes, Hymenocera and Stenopus have received special attention, mainly due to their growing demand in the aquarium trade industry (Fiedler, 1994; Fletcher et al., 1995; Palmtag and Holt, 2001; Lin et al., 2001).
Apart from fin fishes, a wide range of invertebrates are found good to be kept in captivity. These include shrimps, sea anemones, starfishes and tubeworms that make their home on and around the rocks and corals alternatively, we can keep invertebrates alone in an aquarium so as to protect them from the unwelcome attentions of predatory fishes, which allow us to study their lifestyles more easily. Most tropical invertebrates are magnanimously beautiful and attract the viewer’s attention with fascinating behavior patterns (Mills, 1987).
Majority of marine invertebrate resources encountered in the warm seas of the world are more colourful. Information on marine ornamental invertebrate resources is important for an aquarist who wishes to establish an effective invertebrate aquarium. Studies on ornamental invertebrate’s resources are not available globally. Calado et al. (2003) studied only the resources of marine ornamental decapods and its popularity, in global ornamental trade. Information about ornamental invertebrate resources is helpful to biologist, aquarium traders and hobbyists. In this backdrop, this study explores the marine ornamental invertebrate resources of Parangipettai coastal waters, southeast coast of India.
MATERIALS AND METHODS
Description of the Study Area
In the present study, an extensive survey of ornamental invertebrates has
been made from the Parangipettai coastal waters and Vellar estuary (Latitude
11°29’ N, Longitude 79°46’ E), Southeast coast of India (Fig.
1). The Vellar estuary viz., located at Parangipettai which is one of the
fertile estuary in Tamil Nadu. Nearly 1.5 km upstream from the mouth at the
tidal zone and in the northern bank of the estuary, a mangrove plantation covering
an area of 10 ha was planted some 10 years back, by the Center of Advanced Study
in Marine Biology. Being a tidal and bar built estuary, Vellar estuary has semi
diurnal tides and the tidal flushing extends to a distance of about 10 km. The
estuary is an open type with tidal the amplitude ranged from 1 to 1.5 m. The
specimens were collected and recorded from the Annankoil landing center (Station
I) and Vellar estuary (Station II) which was opposite to the Marine Biological
Station.
The craft used for venturing to fishing grounds of Parangipettai coast are mostly indigenous, such as catamarans, fiber launches with lambardini engines, which are operated in sea and dugout canoes, which are employed in Vellar estuary. The gears employed are also mostly indigenous such as gillnets, trawlers, hooks, lines etc. in sea and mainly cast nets etc. in Vellar estuary. In Station I Annankoil landing center is a major landing center of the Parangipettai coastal regions. Fibre launches, catamarans and less number of dugout canoes catches are landed in this center. Many dugout canoes and less number of fiber launches catches are landed in Station II (Vellar estuary).
| Fig. 1: | The study area of Vellar estuary |
Collection Procedure
The ornamental invertebrates were collected (5 collections/month) with the
help of local fisher folk by the operation of trawl net in open sea through
mechanized boat and by soft nylon cast net from canoes. Lobsters were collected
by bottom gill net and hand picking method with the help of fishers (which was
attached with the launches) (adopted from Jackman, 1974).
Good quality specimens of jellyfishes were collected by surface watching over open sea and estuary from the boat. On sighting a live jellyfish, plastic bucket WAS dipped under the jellyfish with some quantity of water and lifted up, this type of collection provided undamaged specimen (adopted from Jackman, 1974). Lepas were collected from different kinds of hard and soft floating substratum associated with by catches and entangled with the net. Green mussel Perna viridis attached with the hard substratum, were entangled with the net from Vellar estuary were also collected. Uca crabs and land hermit crabs were collected from intertidal regions of Vellar estuary through handpicking. Its abundance was recorded by Line transect method (English et al., 1975).
Preservation
The invertebrates were characterized and segregated from consumable fishes,
their numbers were recorded and each individual species was preserved (Lincoln
and Sheals, 1979) in 5% neutralized formalin for further identification.
Identification and Classification
For the identification, classification was carried out with the help previous
research by Russell (1970), Sethuramalingam and Ajmal Khan (1991), Ajmal Khan
(1992), Lyla et al. (1997), Zeiller (1974) and Clark and Rowe (1971).
Diversity Indices, Richness and Evenness
From the obtained data the various indices like species diversity, richness
and evenness were calculated by using the standard formulae as given below:
Shannon-Wiener Diversity (H')
Species diversity was calculated using the following formula of Shannon
and Wiener (1949).
H'=-Σspi log pi
I=1
Which can be rewritten as:
Where,
| H' | = | Species diversity |
| Ni | = | No. of individuals of the ith species |
| N | = | Total No. of the individuals in the collection and |
| Σ | = | Sum |
Simpson Index (D')
Species richness (D) was calculated using the following formula given by Simpson (1949).
D = 1 – C
Where,
| C | = | ΣPi2 |
| D | = | 1-C |
| Pi | = | ni/N |
| ni | = | No. of individuals of i1, i2, etc. |
| N | = | Total No. of individuals |
Pielou’s Evenness (J')
Evenness or equitability (S) was calculated using the formula of Pielou (1966).
J' = H'/Jns or H'/log 25
Where,
| J' | = | Evenness |
| H' | = | Species diversity and |
| S | = | Total No. of species. |
RESULTS
Marine ornamental invertebrate resources of Parangipettai are shown in Table 1 and 2. In this present study 28 species of marine ornamental invertebrates belonging to 4 phyla were recorded from Parangipettai coastal waters and Vellar estuary during the period of 6 months from March 2006 to August 2006.
| Table 1: | Marine ornamental invertebrate resources of Parangipettai |
| Table 2: | Marine ornamental invertebrate resources from two different landing centers of Parangipettai |
| T: Present, -: Absent | |
The most abundant species recorded during the study period was fiddler crab Uca annulipes, where as sea star Ludia maculata was found least in its abundance.
Month among the 28 species recorded during the study period only 19 were recorded in the month of March, in which short stalked goose barnacle Lepas anserifera was recorded top in their abundance, where as species like spider crab Doclea ovis, sand lobster Thenus orientalis, hermit crab Clibanarius longitarsus, land hermit Coenobita cavipes and sea urchin Temnopleurus toreumaticus were very least in their number (Table 3). Nine species were not found. In the month of April 23 species were recorded, in which Thenus orientalis was maximum in their number and sea urchin Salmasis virgulata was minimum and six species were not found. In the month of May most of the species (25 species) have shown their presence and only three were not found. During this month the most abundant species were Uca annulipes and jellyfish Chrysaora quinquecirrha, where as brittle star Ophiocnemus marmorata was least in its count. From the month of June to August, 23 individual species were recorded in respective months, among which Uca annulipes stands a top.
| Table 3: | The month wise abundance of marine ornamental invertebrates of Parangipettai coast during March 2005-August 2005 (numbers/month) |
| Table 4: | The species diversity indices, species richness and species evenness of the marine ornamental invertebrates for the study period (March-August 2005) |
Ragged sea hare Bursetella leachii was the minimum in their number during June where as sea star Luidia maculata was least in their count during the month of July and August, respectively.
The ornamental invertebrate diversity varied from 3.0491 to 4.0513 (Table 4). The minimum diversity was observed during the month of March (3.0491) and the maximum was found during the month of April (4.0513). The richness values varied from 3.4136 to 4.0813. The minimum was observed during the month of March (3.4136) and the maximum was found during the month of May (4.0813). The evenness varied from 0.7177 to 0.9084. The minimum evenness was observed during the month of March (0.7177) and the maximum was found during the month of April (0.9084).
DISCUSSION
Balasubrahmanyan (1966) investigated the distribution of crabs in the intertidal regions of Vellar estuary (1959-1961). Nineteen species of brachyuran crabs were recorded so far from the intertidal areas of the Vellar estuary till date. Uca annulipes occurs as one of the dominant species between high water spring to low water neap. Due to the massive populations of U. annulipes and U. triangularis were lodged to a distance of more than 100 m to inhabit the uninundated places. U. triangularis is present in random between high and low tide levels. U. annulipes occurs extensively in the intertidal level in firm muddy and sandy mud places. A large area of mud flats near this station bears Uca as the dominant species. Ajmal Khan et al. (2005) studied the brachyuran crab diversity in four stations of Pitchavaram mangroves and three stations of Vellar mangroves. In stations, U. triangularis and U. annulipes were highly abundant. Among which U. annulipes where is higher number. In the present study the result which obtained was similar with U. annulipes is the most prevalent and dominant species.
Brachyuran crab landings along the Parangipettai coast was reported by Radhakrishnan (1979) who recorded a total of five species, viz., Scylla serrata, Portunus pelagicus, P. sanguinolentus, Podophthalmus vigil and Charybdis feriatus and their annual landings were estimated as 28507 kg (28.5 tons). In this study seven crab species recorded which are suitable for ornamental purpose. Reddi (1935) has described hermit crabs from Portonovo. Thomas (1989) shows the taxonomic position of Indian water hermit crabs with remarks on their distinctive characters, colour patterns and distribution. In the present study, three species of hermit crabs were reported, which had ornamental fantasy. Land hermit crab Coenobita cavipes showed the highest abundance in the months of June, July and August.
Kizhakudan et al. (2004) summarizes the fishery of the sand lobster T. orientalis (Lund) by bottom set gillnets along the Tamil Nadu coast during September 2003 to February 2004. Sand lobsters are generally landed as by catch during shrimp and cephalopod trawl net operation. The resource is most abundant off the northwest and southeast coasts. In Tamil Nadu the trawlers land about 15-30 ton per annum. During this study T. orientalis was caught by by-catches. In the month of April and May their abundance was very high.
Vijayanand (2001) was carried out for a period of one year from January to December 2000, along the Kanyakumari District where a regular fishery of lobsters. Such as Panulirus ornatus, P. versicolor, P. homarus, P. sewelli, P. longipes, Thenus orientalius and Scyllarides elisabethae were recorded in the 38 lobster landing centers (Kanyakumari District) in during this study period. High species diversity, richness and evenness index was observed during the post monsoon and monsoon season. T. orientalius, P. homarus, P. versicolor was also recorded in the present study. Among these three species T. orientalius had shown its highest abundance. The diversity indices of marine ornamental invertebrate resources are descending in post monsoon and summer seasons when compared with the pre monsoon and monsoon. The invertebrate resource minimum diversity (3.0491) was observed during the post monsoon in March and maximum (4.0513) was found during the summer season in April. The ornamental invertebrates minimum richness (3.4136) was observed during the post monsoon in March and the maximum (4.0813) was found during the summer season in May. The ornamental invertebrate resources minimum evenness (0.7177) was observed during the post monsoon in March and maximum (0.9084) was found during the summer season in April.
Most of the recorded marine ornamental invertebrates are not palatable and are thrown on shore as by catch. Indian spiny lobster Panulirus homarus, large size of sand lobster Thenus orientalis, angle crab Charybdis feriataus and green mussel Perna viridis are edible ones, which are also fascinating the aquarium. Perna viridis are recently added in reef aquarium (Toonen, 2003). The discarded invertebrates from the by-catches should be treated as valuable ornamental species, which will give additional livelihood to the fisher folks.
The coral reefs and lagoons in the Gulf of Mannar, Andaman and Nicobar, Lakshadweep Islands provides rich wealth of aquarium fishes, which can be collected in a sustainable way without damaging the coral reefs and can be exported to earn considerable amount of foreign exchange (Sakthivel, 2002). Those reef zones have more attractive marine ornamental invertebrates (sponges, anemones, live corals, flatworms, polychaetes, shrimps, prawns, lobsters, hermit crabs, true crabs, mollusks, sea lilies, feather stars, sea stars, sea urchins and sea cucumbers) when compared to the present study area. So this preliminary investigation from Parangipettai waters will trigger further detailed studies on that wealthy zone. The complete classified data of marine ornamental invertebrate are not available globally and for Indian waters. So a detailed investigation will be needed to improve the ornamental industry.
ACKNOWLEDGMENT
The authors are greatful to Prof. Dr. T. Balasubramanian, Director, CAS in Marine Biology, Annamalai University, Parangipettai for providing the facilities to carry out the work and encouragement.