prawns and shrimps

Prawns and Shrimps

*Dr. T. Kannupandi, Dr. P. Soundarapandian and Dr. N. Rajendran

*Professor (Retd.) Centre of Advanced Study in Marine Biology,

Annamalai University

angrove habitats are rich in shrimp and prawn resources. Commercial prawn fishery yields are greater in the coasts with

luxuriant mangrove forests than where mangroves are absent. Mangrove leaf litter provides an important nutrient base for food webs. During the decomposition of mangrove litter, a large amount of nutrients are released, and detritus food is formed. This detritus food contributes to the prawn and shrimp fishery production. Mangrove waters serve as an essential nursery ground for juveniles of many species of prawns and shrimps. The out‐welled detritus transported to offshore can also provide food and habitat for juvenile shrimps outside mangrove waterways. Thus the prawns / shrimps are highly associated the mangrove ecosystems, leading to make a statement by Macnae (1968) ‐ ʺNo mangroves, so no prawnsʺ. The loss of mangrove habitats must have a serious impact on the densities of prawn / shrimp species.

The order ‐ Decapoda comprises of commercially important species of prawns/shrimps, crabs and lobsters. This order comprises of about 1,100 genera with about 8,321 species, but the figure has been increasing year by year. According to Holthuis (1980), the prawns/shrimps include about 33 genera with about 2,500 species, of which less than 300 species are of economic interest throughout the world. Among the decapod crustaceans, penaeids constitute a distinct group of commercially important species. Due to their nutritional value, they support a very valuable, trade export market. Most of these species come under 5 penaeidean families viz., Solenoceridae, Aristidae, Penaeidae, Sicyoniidae and Sergestidae, and three caridian families viz, Pandalidae, Crangonidae and Palaemonidae. The family Palaemonidae includes two subfamilies, namely Palaemoninae and Pontoniinae. The prawns belonging to the Palaemoninae inhabit inland water bodies, from brackishwaters to hill streams, and very rarely marine. Many are large in size and have potential for aquaculture. The Pontoniinae includes prawns, which are exclusively marine inhabitant. They

M

309 Prawns and Shrimps

generally live in association with other organisms like mollusks and echinoderms and are frequently found among corals. Many of these are brilliantly coloured and hence are of great ornamental value. The species assemblage of the family Palemonidae is vast and diverse. As many as 21 valid genera and around 300 species from different parts of world have been reported under Palaemoniinae. The reported genera and species under Pontoniinae are 72 and 416 respectively. Fully adapted hill stream prawns are only few in numbers. As many as 85 species have been reported to be either of major or minor importance to fisheries. There are 154 known species, reportedly found in the global mangroves (Table 1).

The body of the prawns/shrimps is almost laterally compressed with a toothed rostrum and a longer abdomen than the cephalothorax or head. Antennules in most of the species bear small scales or spines, while the antennae have large plate like scale. The pereopods are slender sometimes large and chelated. The pleopods or the swimming legs are well developed and present on all the abdominal segments.

The genus ‐ penaeus spawns offshore at depths of about 10‐80m and the eggs that hatch within a few hours, release very small larvae, the nauplii. Usually there are 11 larval stages, which include 5 nauplii, 3 protozoea and 3 mysis. The larvae are planktonic and are carried by current towards shore, where they arrive as post‐larvae. This occurs about 3 weeks after hatching when the animals are about 6 to 14 mm long. Then the post‐larvae invade inshore water like mangroves and brackishwater, and they grow in these nursery grounds, develop into juveniles and return to near shore areas, more gradually back towards as they become sub‐adults. Soon these shrimps migrate offshore, continue growing, and finally as adults reach the spawning grounds, and the cycle is repeated.

Importance

Mangroves are of primary importance to fisheries in many ways, plenty of species make use of mangrove ecosystems in various manner, some being obligate i.e. spending their entire life cycle in this ecosystem or a crucial part of it (e.g. Penaeid prawns) using it as shelter or as a source of food; others acultative i.e. being able to survive and reproduce even in absence of mangroves but yet showing preference for the habitats and nutrition provided therein. The mangal acts as a sink for settlement and early growth of shrimps and prawns, it may also be a source for larvae that are transported to other habitats. Mangrove waters in the Klang

T. Kannupandi, P. Soundarapandian and N. Rajendran 310

Strait of Malaysia may collect 65 billion penaeid prawn larvae before their annual transport and settlement in coastal nursery grounds. Tidal currents and lateral trapping in mangrove‐lined channels cause this aggregation (Chong et al., 1996).

Mangrove habitats and shrimp resources are tightly linked in many regions. Analyses of commercial prawn catches have repeatedly shown strong correlation between abundance and biomass of prawns and extent of the mangrove areas (Martosubroto and Naamin, 1977; Turner, 1977; Subramanian and Krishnamurthy, 1990; Sasekumar et al., 1992; Vance et al., 1996). In the Indian mangrove ecosystems, there are a total of 48 prawn species, of which, 34 (71%) in the mangrove rich eastcoast, 16 (33%) in the Bay islands and 20 (42%) in the mangrove poor westcoast have been reported (Kathiresan and Rajendran, 2000). Robertson and Blaber (1992) proposed an explanation for this relationship that the mangrove waterways directly serve as nursery grounds for juvenile shrimps that move offshore and enter the commercial fishery as they mature. This hypothesis is strongly supported by surveys of larval, post‐larval and juvenile shrimps in nearshore habitats (Vance et al., 1990; Parulekar and Achuthankutty, 1993; Mohan et al., 1995; Mohan et al., 1997; Rajyalakshmi, 1991; Primavera, 1998 and Kathiresan et al., 1994). The nutritive value of mangrove leaves for juvenile shrimps that are attracted towards mangroves has been proved (Ramesh and Kathiresan, 1992; Rajendran and Kathiresan, 1999). Numerous species of penaeid shrimps from the Pacific coast of Panama are found in the mangrove channels as juveniles and three species of white shrimps are the most abundant in the tidal mangroves (D’ Croz and Kwiecinski, 1980).

Small‐scale fisheries in mangrove waters produce nearly one million tons of crabs, shrimps, molluscs and finfishes annually; this is equivalent to about 1.1 per cent of the worldʹs total fish catch. Mangroves provide direct employment to about 0.5 million fisherfolk. A total of about one million jobs worldwide is dependent on mangrove‐associated fisheries. The density of population dependent on mangroves is estimated at about 5.6 persons/km2 (FAO, 1988). Besides the capture fishery, culture fishery is also prevalent in the mangrove‐rich areas. To cite an example, 40,000 fishers get an annual yield of about 540 million seeds of Penaeus monodon and 10.26 billion other fish, in the Sundarban mangroves of West Bengal that has a dense deltaic mangroves with numerous sheltered water creeks (Chaudhuri and Choudhury, l994).


In Bangladesh, the fish/shrimp catch records of twelve years (1972 ‐ 1983) reveal an average annual production of 7,163 metric tons (FAO, 1984). Recently Chantarasri (1994) reported that > 10,000 tons of shrimps, fishes and crabs were harvested from the Sundarban ecosystem in the year 1993. About 334 million tiger shrimp fries were also collected by about 110,000 fishermen (Chantarasri, 1994) from the mangrove ecosystem. The mangrove ecosystem of Tutoia, Maranhao, near the Piacci border (Brazil) supports 1,800 mostly artisanal fishermen, who caught 1,162 tons of penaeid shrimp in 1977 (SUDAM/UFMA, 1981) and in Baia de Sepetiba, Rio de Janeiro, where 3,200 ha of mangroves yield between 100 and 200 tons of shrimps annually (Laurda et al., 1988).

Collection and Preservation

Penaeid prawns can be collected using different types of nets viz. Drag net, Stake net, Cast net, Dip net, Bag net, Barrier net, Scoop net, Push net, and Gill net in the coastal water bodies like mangroves, estuaries, bays, and lagoons etc. The trawl nets (Beam trawl, Otter trawl), Seine nets (Boat seine, Beach seine or Shore seine) and Fyke nets are used usually in the open water bodies. After collection, the specimens are preserved in 5% of formaldehyde solution and then the specimens can be identified using the standard keys.

Identification Techniques

In general, the penaeid prawns and non‐penaeid prawns can be identified using morphological characters. For e.g., the pleurae are arranged regularly in the penaeid prawns and in the non‐penaeid prawns the pleurae of the second abdominal segment are overlapping those of first and third segments. The third pereopods are not chelated in the non‐penaeid prawns but chelated in the penaeid prawns. Also, abdominal segment has a sharp bend in the non‐penaeid prawns but not in the penaeid prawns.

In penaeid prawns, the distinguished identical characters are the rostral structure, rostral teeth, antenna colouration and body colour with strips. In majority of the penaeid prawns, rostral teeth are important characters to distinguish the different species and also within the groups. For e.g., in Penaeus species the rostral teeth are present both in the upper and lower portions of the rostrum, but in case of Metapenaeus species the rostral teeth are present only in the dorsal side of the rostrum, but not in the ventral side.


Factors Affecting the Biodiversity

The changes in benthic communities could be attributed to the direct or indirect effects of reduced salinity. Reduced salinity during monsoon season affects the species diversity (Vance et al., 1985). In general, the juvenile shrimps are abundantly occurring in the moderate salinity. Hence the discharge of freshwater in the estuarine system is essential for the growth of many prawn species. Any action to change the freshwater sources may affect the prawn distribution. The oil spills that occur often in many areas settle in the bottom soil, and affect the benthic faunal diversity.


Denudation of mangroves cause direct effect to the prawn fishery. For instance, in Vedaranyam (southeast India), there was a 40% loss of mangrove forest, which coincided with an 18% decline in fishery resources within a 13‐year period between 1976 and 1989 was reported (Padmavathi, 1991). The shrimp production of the Cochin backwater has fallen almost to nil due to the clearance of extensive mangrove cover by the people living around the backwater (Mastaller, 1996). There is a marked difference in the density of penaeid juveniles in the mangroves and denuded non‐mangrove areas, as reported in Sri Lanka by Costa (1995). The removal of 50% of the mangroves affected the 40% of the shrimp catch in Malaysian water was reported (Chong et al., 1996).

Comparison with other Environment

The abundance of shrimp juveniles in mangrove area was noted to be higher than non‐mangrove areas. The penaeid prawn harvest was recorded to be 10 fold higher in mangrove ‐ rich area than mangrove ‐ poor area (Kathiresan and Rajendran, 2002) and the prawn resource in degrading mangrove waters was found lower than that in the luxuriant ones (Kathiresan, 2002). The juveniles were also found more abundant in sheltered water creeks than in open water bodies of mangroves (Rajendran, 1997). In Oman, Mohan and Siddeek (1996) similarly found abundant post‐larval and juvenile shrimp in the detritus – rich, muddy substrata of a mangal than other areas. The numbers and biomass of prawns and shrimps are generally higher in mangrove areas than in adjacent near shore habitats (Chong et al., 1990; Sasekumar et al., 1992; Primavera, 1998).

Table 1. List of penaeid and non‐penaeid prawn species reported in the global mangroves

S. No. Category Genus/species 1 Penaeidae Atypopenaeus stenodactylus (Stimpson) 2 Macropetasma africana (Balss) 3 Metapenaeopsis barbata (De Haan) 4 M. crassissima Racek and Dall 5 M. goodei (Smith) 6 M. palmensis (Haswell) 7 M. stridulans (Alcock) 8 M. coniger (Wood Masson) • 9 Metapenaeus monoceros (Fabricius) • 10 M. affinis (Milne Edwards) = M. mutatus (Lanch.) • 11 M. brevicornis (Milne Edwards) • 12 M. dobsoni (Miers) •


13 M. lysianassa (de Man) • 14 M. ensis (de Haan) =M. mastersi (Hasw.) 15 M. benettae Racek and Dall 16 M. conjunctus Racek and Dall 17 M. dalli Racek 18 M. demani (Roux) 19 M. elegans (de Mann) 20 M. endeavouri (Schmitt) 21 M. intermedius (Kishinouye) 22 M. kutchensis George and Rao • 23 M. macleayi (Haswell) 24 M. moyebi (Kishinouye) = M. burkenroadi Kubo • 25 M. stebbingi Nobili 26 M. tenuipes Kubo = M. spinulatus Kubo 27 Metapenaeus sp. • 28 Parapenaeopsis acclivirostris Alcock 29 P. atlantica Balss 30 P. cornuta (Kishinouye) 31 P. hardwickii (Miers) • 32 P. maxillipedo Alcock 33 P. longipes Alcock • 34 P. sculptilis (Heller) • 35 P. stylifera Milne Edwards • 36 Penaeus aztecus Ives 37 P. braziliensis Latreille 38 P. brevirostris Kingsley 39 P. californiensis (Holmes) 40 P. canaliculatus (Olivier) • 41 P. chinensis (Osbeck) = P. orientalis Kishinouye 42 P. duorarum (Burkenroad) 43 P. esculentus Haswell 44 P. indicus Milne Edwards • 45 P. japonicus Bate • 46 P. kerathurus (Forskal) 47 P. latisulcatus Kishinouye • 48 P. marginatus Randall 49 P. merguiensis de Man • 50 P. monodon Fabricius • 51 P. semisulcatus de Haan • 52 P. notialis Perez‐Farfante 53 P. occidentalis Street 54 P. penicillatus Alcock • 55 P. plejebus Hess 56 P. schmitti Burkenroad 57 P. setiferus (Linnaeus)


58 P. stylirostris Stimpson 59 P. subtilis Perez‐Farfante 60 P. vannamei Boone 61 Pleoticus muelleri (Bate) 62 Protrachypene precipua Burkenroad 63 Trachypenaeus byrdi Burkenroad 64 T. constrictus (Stimpson) 65 T. curvirostris (Stimpson) 66 T. fulvus Dall 67 T. sedili Hall 68 T. similis (Smith) 69 Xiphopenaeus kroyeri (Hellar) 70 X. riveti Bouvier 71 Sergestidae Acetes americanus Ortmann 72 A. australis Colefax 73 A. erythraeus Nobili • 74 A. indicus Milne Edwards • 75 A. sibogae Hansen 76 Acetes sp. • 77 Sergestes intermedius Omori 78 Sicyoniidae Sicyonia brevirostris Stimpson 79 S. stimpsoni Bouvier 80 S. typica (Boeck) 81 Solenoceridae Solenocera crassicornis (Milne Edwards) • 82 Palaenonidae Cryphiops caementarius (Molina) 83 Exopalaemon carinicanda (Holthuis) 84 E. modestus (Heller) 85 E. orientis (Holthuis) 86 E. styliferus (Milne Edwards) 87 Leander tenuicornis 88 Leptocarpus fluminicola (Kemp) 89 L. potamiscus (Kemp) 90 Macrobrachium acanthurus (Wiegmann) 91 M. americanus Bate 92 M. australe (Guerin) 93 M. birmanicum (Schenkel) 94 M. carcinus (Linnaeus) 95 M. equidens (Dana) 96 M. idella (Hilgendrof) • 97 M. idea (Heller) • 98 M. jelskii (Miers) 99 M. lamarrei (Milne Edwards) • 100 M. lanchesteri (de Mann) 101 M. lar (Fabricius) 102 M. dayanum (Henderson) •


103 M. javanicum (Heller) • 104 M. latidactylus (Thallwitz) 105 M. latimanus (von Martens) 106 M. macrobrachion (Herklots) 107 M. malcolmsoni (Milne Edwards) • 108 M. mirabile (Kemp) • 109 M. nipponense (de Haan) 110 M. ohione (Smith) 111 M. rosenbergii (De Man) • 112 M. rude (Heller) • 113 M. scabriculum (Heller) • 114 M. tenellum (Smith) 115 M. vollenhoveni (Herklots) 116 Nematopalaemon hastatus (Aurivillius) 117 N. schmitti (Holthuis) 118 Palaemon concinnus (Dana) • 119 P. debilis Dana • 120 P. macrodactylus Rathbun 121 P. maculatus (Thallwitz) 122 P. styliferus Millne Edwards • 123 P. pandaliformis (Stimpson) 124 P. semmelinkii (De Man) • 125 P. tenuipes (Henderson) = Nematopalaemon tenuipes

(Henderson) • 126 Palaemonetes intermedius (Holthuis) 127 P. pugio Holthuis 128 P. vulgaris (Say) 129 Alpheidae Alpheus lobidens de Haan 130 A. euphrosyne de Man 131 A. heterochaelis Say 132 A. malabaricus Fabricius • 133 A. crassimanus • 134 A. paludicola Kemp • 135 Alpheus sp. • 136 Atyidae Atya gabonensis Giebel 137 A. pilipes Newport 138 A. sulcatipes Newport 139 Caridina gracilirostris de Man • 140 C. nilotica (Roux) 141 C. brachydactyla Kemp • 142 C. propinqua de Man 143 Crangonidae Crangon septemspinosa Say 144 C. nigromaculata Lockington 145 Laomedia astacina (de Haan) 146 L. healyi Yaldwin


147 Hippolytidae Exhippolysmata ensirostris (Kemp) 148 E. hastaoides (Balss) 149 E. oplophoroides (Holthuis) 150 Toreuma carolinense Kingley 151 Luciferidae Lucifer hanseni Nobili • 152 Lucifer sp. 153 Thalassinidae Thalassina anomala (Herbst) • 154 Upogebidae Upogebia affinis

• Species reported in the Indian mangroves (Sources: Holthuis, 1980; FAO, 1988; Das and Dev Roy, 1989; Chaudhuri and Choudhury, 1994; Chanda and Sekhar Kar, 1999; Kathiresan and Rajendran, 2000).

References Chantarasri, S. (1994). Integrated resource development of the Sundarbans

reserve forests. 4th draft report on Fisheries Resource Management for the Sundarbans Reserve Forest, Khulna, Bangladesh (BGD/84/056). FAO, UNDP, 171 pp.

Chanda, S. and Sekhar Kar, C. (1999). Bhitarkanika : Myth and Reality. Nataraj Publishers, Dehradun, 388 pp.

Chaudhuri, A.B. and Choudhury, A. (1994). Mangroves of the Sunderbans, India, 1 : 247 pp.

Chong, V.C., Sasekumar, A., Leh, M.U.C. and D’Cruz, R. (1990). The fish and prawn communities of a Malaysian coastal mangrove system, with comparisons to adjacent mudflats and inshore water. Estuarine, Coastal Shelf Science, 31(5) : 703‐722.

Chong, V.C., Sasekumar, A. and Wolanski, E. (1996). The role of mangroves in retaining penaeid prawn larvae in Klang Strait, Malaysia. Mangroves and Salt Marsh, 1 : 1‐22.

Costa, H.H. (1995). The effects of denudation of mangroves on the abundance and distribution patterns of juvenile prawns in an estuarine lagoon of Sri Lanka. In: Mahmood, N. (Ed.), Proceedings of the workshop on Coastal Aquaculture and Environmental Management. Organized by Institute of Marine Sciences, University of Chittagong, Bangladesh, pp. 1‐5.

Das, A.K. and Dev Roy, M.K. (1989). In: Jairajpuri, M.F. (Ed.), A general account of the mangrove fauna of Andaman and Nicobar islands. Zoological Survey of India, Calcutta, 173 pp.


D’Croz, L. and Kwiecinski, B. (1980). Contribution de los manglares a las pesquerias de la Bahia de Panama. Revista de Biologia Tropical, 28 (1) : 13‐29.

FAO (1984). Integrated development of the Sundarbans, Bangladesh. Fisheries Integrated Development in the Sundarbans based on the work of H.R. Rabanal. FO: TCP/BGD/2309, 75 pp.

FAO (1988). Worldwide compendium of mangrove associated aquatic species of economic importance. FAO Fisheries Circular No.814 (FIRI – C814), Rome, 236 pp.

Holthuis, L.B. (1980). FAO species catalogue. Vol.1. Shrimps and prawns of the world. An annotated catalogue of species of interest to fisheries. FAO Fisheries Synopsis (125), 1 : 261 pp.

Kathiresan, K. (2002). Why are mangroves degrading? Current Science, 83(10) : 1246‐1249.

Kathiresan, K. and Rajendran, N. (2000). Flora and fauna in Indian mangrove ecosystem: East coast. In: Kathiresan, K. (Ed.), Flora and fauna in Mangrove ecosystems: a manual for identification, pp. 1‐49.

Kathiresan, K. and Rajendran, N. (2002). Fishery resources and economic gain in three mangrove areas on the southeast coast of India. Fisheries Management and Ecology, 49 (5) : 277‐283.

Kathiresan, K., Xavier Ramesh, M. and Venkatesan, V. (1994). Forest structure and prawn seeds in Pichavaram mangroves. Environment and Ecology, 12 (2) : 465‐468.

Laurda, J.D., Koudstal, R., Bower, B.T. and Pfeiffer, W. (1988). Sepetiba Bay management study. IFIAS Research Program on Coastal Resources Management. The International Foundation of Institute for Advanced Study, Rio de Janeiro.

Macnae, W. (1968). A general account of the fauna and flora of mangrove swamps in the Indo‐west Pacific Region. Advances in Marine Biology, 6 : 73‐270.

Martosubroto, P. and Naamin, N. (1977). Relationship between tidal forests (mangroves) and commercial shrimp production in Indonesia. Marine Research of Indonesia, 18 : 81‐86.

Mastaller, M. (1996). Destruction of mangrove wetlands – causes and consequences. Natural Resources and Development. Institute for Scientific Co‐operation, Tubingen, Federal Republic of Germany, vol. 43/44.

Mohan, R. and Siddeek, M.S.M. (1996). Marine habitat preference, distribution and growth of post‐larvae, juvenile and pre‐adult Indian white shrimp, Penaeus indicus H. Milne Edwards, in Ghubat Hasish Bay, Gulf of Masirah, Sultanate of Oman. Fisheries Management and Ecology, 3 (2) : 165‐174.


Mohan, P.C., Rao, R.G. and Dehairs, F. (1997). Role of Godavari mangroves (India) in the production and survival of prawn larvae. Hydrobiologia, 358 (1‐3) : 317‐320.

Mohan, R., Selvam, V. and Azariah, J. (1995). Temporal distribution and abundance of shrimp post larvae and juveniles in the mangroves of Muthupet, Tamil Nadu, India. Hydrobiologia, 295 : 183‐191.

Padmavathy, M. (1991). In: Proceedings of National Symposium on Remote sensing on environment. Chennai, Anna University, pp. 8‐10.

Parulekar, A.H. and Achuthankutty, C.T. (1993). Resource potential of juvenile marine prawns in the estuarine of Goa. Publisher Technical Report (NIO/SP‐2/93), 85 pp.

Primavera, J.H. (1998). Mangroves as nurseries: shrimp populations in mangrove and non‐mangrove habitats. Estuarine Coastal Shelf Science, 46 (3) : 457‐464.

Rajendran, N. (1997). Studies on mangrove associated prawn seed resources of Pichavaram, southeast coast of India. Ph.D. Thesis, Annamalai University, India, 135 pp.

Rajendran, N. and Kathiresan, K. (1999). Seasonal occurrence of juvenile prawn and environmental factors in a Rhizophora mangal, southeast coast of India. Hydrobiologia, 394 : 193‐200.

Rajyalakshmi, T. (1991). The prawn fisheries of the Godavari estuarine system Kakinada Bay complex. Journal of Inland Fisheries Society of India, 23 (2) : 50‐59.

Ramesh, M.X. and Kathiresan, K. 1992. Mangrove cholesterol in the diet of penaeid prawn Penaeus indicus. Indian Journal of Marine Science, 21 (2) : 164‐166.

Robertson, A.I. and Blaber, S.J.M. (1992). Phytoplankton, epibenthos and fish communities. In: Robertson, A.I. and Alongi, D.M. (Eds.), Coastal and Estuarine studies: Tropical mangrove ecosystem, Washington, DC, USA: American Geophysical Union, pp. 173‐224.

Sasekumar, A., Chong, V.C., Leh, M.U. and D’cruz, R. (1992). Mangrove as a habitat for fish and prawns. Hydrobiologia, 247 : 195‐207.

Subramanian, P. and Krishnamurthy, K. (1990). Mangroves: The diplomats of Neptune’s court. Environment and Ecology, 8 (2) : 659‐663.

SUDAM / UPMA (1981). Ocamarao na area de Tutoia – Maranhao. SUDAM. Belem, 135 pp.

Turner, R.E. (1977). Intertidal vegetation and commercial yields of penaeid shrimp. Transaction of the Amerian Fisheries Society, 106 (5) : 4111‐4116.

Vance, D.J., Staples, D.J. and Kerr, J.D. (1985). Factors affecting year to year variation in the catch of banana prawns (Penaeus merguiensis) in the


Gulf of Carpentaria, Australia. Journal du Conseil, Conseil International pour d’ Exploration de la Mer, 42 : 83 – 97.

Vance, D.J., Haywood, M.D.E. and Kerr, J.D. (1990). Use of mangrove estuary as a nursery area by postlarval and juvenile banana prawns, Penaeus merguiensis de Man, in northern Australia. Estuarine, Coastal Shelf Science, 31 (5) : 689‐701.

Vance, D.J., Haywood, M.D.E., Heales, D.S. and Staples, D.J. (1996). Seasonal and annual variation in abundance of post larval and juvenile grooved tiger prawns Penaeus semisulcatus and environmental variation in the Embley River, Australia: a six year study. Marine Ecology Progress Series, 135 : 43‐55.

prawns and shrimps

Documents