PRODUCTION , SIZE DISTRIBUTION , AND LENGTH WEIGHT RELATIONSHIP OF LOBSTER LANDED IIU THE SOUTH COAST OF YOGYAKARTA , INDONESIA

Lobster is one of the most important fisheries export commodities. An increasing trend of annual production during 1999-2005 was occurred, however a decreasing trend during 2005-2007 was observed. lt is likely that the long lived and slow growing species group do not capable to balance the fishing pressure. Information on lobster fisheries were gathered through desk study while field surveys and biological observations were focused in Baron sub district at the largest lobster collector in the district of Gunung Kidul, Yogyakarta. From data analysis it was found that the dontinant size of lobster collected in January to October 2009 was in the stage of juvenile or can be categorized as seed with the monthly average of about 52% of the total catch. ltwas also identified that lobster species consisted of sand lobster (Panulirus homarus), brown spirry lobster (P, penicillatus), pearl lobster (P. ornatus), dark green striped leg spiny lobster (P. versicolor), painted spirry lobster (P. longipes), grey-blue spotted legs (P polyphagus), and red Spanish lobster (Scyllarides squammosus). The first tvuo species were the rnost abundance group as reflected by the highest amount in the catch followed by P ornatus. Lobster fishing season characterized by high production in the soutlr coast of Yogyakafta occur at the end of the year to the beginning of the following year. Some managenrent measures leading to the optimum and sustainable yield of lobster fisheries in the south coast of Yogyakarta include application of rninimum legal size and protection of parent stock at the collector level should be introduced.


INTRODUCTION
lobster, South Coast ofYogyakarta, seeds of lobster Lobster is an important marine fisheries commodity in Indonesia, even in other parts of the world, current and future.Percentage of lobster exports compared to production of shrimp in 2006 was about 2.3%.From the year 1999-2006 lobster exports continued to increase, with average of 9.1o/o, with European Union, Table 1 Japan, and the United States as the countrees of destination.
Lobster is an Indonesian important fisheries export commodities, that cover vride market area to all the continents of the world.The largest export destination was the Asian countries as shown on Table 1.
In the world market, there are currently four known lobsters; the true lobster-Homaridae, spiny lobster- Palinuridae, cray fish-Astacidae, and Spanish lobster-Scyllaridae.Three types of lobsters, the cray fish, spanish lobster, and spiny lobster are known to be present in lndonesia (Subani, 1981).Four species of fu:4: PERPUSTAKAAN Ind.Fish Res.J. Vol.16 No.1 June 2010: 15-24   lobster that are internationally harvested on a com mercial basis include American lobster ( Homa ru s a merican u s), European lobster (Hom a ru s g a m ma ru s), spiny lobster (Panulirus spp.), and rock lobster (Jasus spp.).Most of lobster groups in Indonesian waters belong to the family Palinuridae, consists of five genera; Justitia, Linuparus, Palinustus, Panulirus, and Puerulus, represented by 19 species including the six genera that commonly represented in Indonesian waters (FAO, 1998).
Based on their distribution lobster are grouped in different types of habitat (FAO, 1998; Moosa &   Aswandy, 1984; Kanna, 2006), ie lobsterthat live in coastal waters a nd shal low reefs/continental species (P.homarus and P penicillatus), lobster that live in coral waters/coral species (P.longipes and P. versicolor, P. ornatus, and P femoristriga) and lobster that live in offshore/oceanic species (P polyphagus).
The ever increasing trend of lobster annual production in Indonesia during 1999-2005 was observed, and a decreasing trend in the following twoyears was occurred (Anonymous, 2007) (Figure 1).
From this description, it was likely that lobster exploitation that lead to the decline in population is due to the high market demand.This is related to the biological nature of these species group that are belong to the long lived and slow growing species (Lagler et al., 1977; Subani et al., 1982; Herianti,   1997).As it is known that lobster life cycle and the gradual development in general can be divided into the following stadia; egg stadia (9-12 months), prelarvae (1-1.5 months), larvae (12 days to 1,5 months), itwas informed thatfrom post larvae stadia untilthe comolete transformation or reach adult ohase will need 5-8 years (www.lobster.um.maine.edu/).i+r Annual trend of lobster oroduction of Indonesia.lobster fishing area in South Coast of Java beside South Coast of Central and West Java.
In this study, data analyzed were collected from a number of primary and secondary data.Primary data includes biological data such as identification of lobsterspecies and length weight measurementwere obtained by sampling at the biggest collector in Baron.Secondary data include reports of lobsters landed in Baron landing site, statistical data from both the Director General of Capture Fisheries and District of MarineAffairs and Fisheries Services of Gunung Kidul, and also notes of lobster collector.This study try to elucidate the production, size distribution, and length weight relationship of lobster in relation to the importance of lobster commodity and to manage the resources, due to very limited information avalaible on lobster resources expecially in the South Coast of Yogyakarta.

MATERIALSAND METHODS
The research was conducted on Seotember and October 2010 in Baron, South Coast of Yogyakarta.
The location of sampling site has been chosen based on available information that is one of the quite large Species identifications were mainly based on Chan W =a Lb ................ ( 1(1998); Moosa & Aswandy (1984).Carapace length was measured in cm unit and weight in gram.where: Carapace length (CL or: cl., distance from the median W = weight (g) supra-orbital horns to the median posterior carapace L = csfdPdce length (cm) margin); total length (TL, distance from the median a = intercept supra-orbital horns to the tip of the telson with the b = slope abdomen fully extended) (Figure 2).All measurements are in centimetres.Length and weight relationship Others aspects regarding lobster fishery were followtheequation, (Effendi,2002): gathered through observations, interviews, and literature studies.General shape of a Spiny lobster.

Lobster fisheries in Yogyakarta
In Yogyakarta Province, lobsters provide one of the ten most important fisheries production (Anonymous, 2008).Although the contribution in weight was only 3%, but the value reached to about Rp.2.g billion, almost the iame amount obtained from Table 2.
jaring sirang with the principle dimension of 4-6 m depth, 30-40 m length, and of 8-10 cm mesh size for one piece of gillnet (Figure 4b).Lobster caught by these gear is usually entangle.Krendet is a passive fishing gear placed in the cracks of rocks or in shallow water on rocky shore.The form are vary f rom round, rectangular to oval.Physically, krendet fishing gear consists of several parts, ie frame, webbing, ropes and bait ropes.ln general, the framework made of bamboo, wood, rattan, and iron.Diameter frame size is usually between 80-100 cm.Webbing was made from polyamid with meshsize 1.75-4.5 inch, consist of 1-3 piece.Rope was made form polyethilen, 4-6 mm diameter, 2 m long.The diameter of bait rope between 1-2 mm in length varies according to the diameter of the framework.The catch of lobster usually done in shallow reefs.and some other olaced the krendet at the edge of a cliff during a night.Average of daily catch around 0.5-3 kg. 5 t,i, 4rr; 1 ii';r E ,t='.nf,,f+et.t,Sfl ,tr'.;g;1,i,;-,i,f,f,3+r.r,.. g p. ;',;:,,i,;',i1ig;i !,Et r:-t,r,rl,',f ,f ,:; tr ,rI' ',rp,r5; jr;:rlr,t'iirl El ,5' ,:r ill,; Iil,'jl,:,,:;,1.,,:iAccording to Wirosaputro (1996), the composition of fish and lobster production recorded in TPI Baron was 5:1 (fishes = 83.20ohand lobsters 16.8%).There was a tendency of this proportion to change leading to a decreased of lobster proportion in the catches.

Prod. (to16)
Suadi ef al. (2001) describes that the fluctuation of trend of catch per unit effort from 1988 to midle of 2000 tend to increase.Meanwhile, by using statistical data (2007-2008) by using krendet data, shown decreasing of catch per unit effort from 2.4-1.6 kgl trio.
Based on lobster data reported in Baron suggests that in general a lot of lobster caught in the rainy season, which is around November to January or at the end of the year to the beginning of the following year.This situation is similar with lobster fishing season in south coast of Kebumen (Argopeni, Karangduwur, and Pasir landing sites).In general, the highest annual production occured in November or December and the lowest production in August, while the catch in March to July was negligible.

Size Distribution
From sampling activities carried out in September until October 2009, it was found that the individual size of lobsters range between 4.1-14.1 cm carapace length or total length of 10.3-34.8cm, with the range of weight from 30-1,000.2g.From sampling data analysis it was found that the dominant size of lobster collected in September and October 2009 was in the stage of juvenile or can be categorized as seed (30- 1 00 g) average of about 52o/o ol the total catch.Some berried females were commonly found in the fish markets, This lack of spawner protection could damage reproductive potential of the lobster population that Lobster annual prod uction recorded in Baron TPI from  2001-2008 was sharply fluctuated (Figure 5), with the maximum of around 3.37 tons occurred in 2003, that was likely similar to the statistical data of Yogyakarta.
--*-Yogyakarta Provinc e --r-Barnn {x 0.1) lead to the recruitment failure that resulted in declining lobster population.As reported by Chang et al. ( 2007) a minimum legal size should be established for the fishery to protect egg production potential of lobster population.Since 1995, concern to catch berried lobster has arisen as they were usually discarded or cheaply sold almost at the same price with the unberried ones.In fact, berried female is very important as seeds supplier for the conservation of natural biological resources of the lobster (Wirosaputro, 1996).
Weight freq uency d istribution data ol 342 specimen of seven species ol Panulirus spp.collected by random sampling ranging from 0.03 kg (30 g) until 1.03 kg (1,030 g) has been available.The'super grade' (starting from the size of 0.1 kg/100 g) was the most expensive.
While in the international market, as reported by the FAO-Infofish (Smith, 1995), the lowest grade was 0.45 kg (450 g or equal to 1 lb), and the highest grade was 2.25k9 (2,250 g or equal to 5 lbs).
Overall samples of six species of lobster was dominated by the size of 100-150 g (Figures 6 and 7).
It is appeared that the dominant size of lobster measured in September and October 2009 was in the stage of juvenile or can be categorized as seed.
Badrudin ef a/. (2005)reported that the size of lobsters caught in July untilAugust 1997 was dominated by the group of 100 g, whereas in the next month (September 1997), the catch was dominated by the group size of 150 g.

Length-Weight RelationshiP
Length weight relationship of Panulirusspp., based on sample collected from fishers are presented in Table 3. Results of the t-test of the b = 3 value for P homarus, P. penicilatus, P. longipes, P. ornatus, and P versicolorwas statistically not significant, meaning Table 3. oS ol3 of o+ oF of $f 5f s?q o+ *s kg Weight frequency distribution of lobster in January to March 1998 (Yogyakarta).
Source: Badrudin et al. (2005)   that the groMh pattern of the five species in the south coast of Yogyakarta was isometric.F-test used to determine how the influence of independent variable to the dependent variable.From results the F{est for all species, Fu",u" larger than F,"0,"(Fu"ru")F,"or") this means that the regression models significantly  (1994) reported that the growth pattern of Panulirus homarus in Pangandaran and West Aceh (Suman & Subani, 1993) was negative allometric.This growth pattern implies that the two species were likely more slender, where growth in length is faster than growth in weight.This is in contrast to the growth of lobsters in the South coast of Bali, that indicates the positive allometric pattern indicating that the lobster is fat or plump.The differences of growth pattern would likely due to higher nutrient level in certain waters that lead to accelerate lobster feeding behavior.
"+d (Figure 8), with the peak at the end of the year to the beginning of the following year.Further analysis shown that in the end of the year the juvenille stage lead tc decrease in contrast to larger size that re 'atively increase.Some management measures that lead to the optimum and sustainable yield in the South Coast of Yogyakarta needs to be proposed.From data analysis it was found that the dominant size of lobster collected in January to October 2009 was in the stage of juvenile or can be categorized as seed with the monthly average of about 84/" of the total catch, and the highest percentage occurred in January (94%) (Figure 13).Seed abundance pattern is similar to the pattern of the lobster fishing season .tt.t'jf'rr* i, ;*'3*'.r;lsdF**f Figure 1.
Figure 2.General shape of a Spiny lobster.
Province distributed along the coastal waters of the districts of Gunung Kidul, Bantul, and Kulonprogo, of which Gunung Kidul contribute the most contributor in lobster production in 2008.The five landing places that function also as the market of lobster in this province include Sadeng, Wediombo, Drini, Baron, and Norenehan.The ten most imoortant recorded fisheries oroduction in 2007 species landed in Yogyakarta consisted of six species of the genus Panulirus and one of the genus Scyllarides.The species of the genus Panulirus include Panulirus homarus (sand lobster), Panulirus penicillatus (rock lobster), P. ornatus (pearl lobster), P. longipes (painted spiny lobster or white spotted red spiny lobster), P. versicolor (bamboo lobster or dark-green striped leg), and P. polyphagus (grey-blue 1-' ITlnd.Fish Res.J. Vol.16 No.1 June 2010: 15-24 spotted legs) while Scyllarides squammosus (red Spanish lobster) forms the only species of the genus Scyllarides.From landing data it was found that the first four species o'f Panulirus provide the mosr dominant that cover almost 99"h of lobster landing.Suadi et al. (2001) reported that fishermen in the South Coast of Yogyakarta approximately 2000 people.This amount included the trap (locally called krendet) fishermen.Meanwhile, in 2003, it was reported that fishermen Gunung Kidul varied based on regions and season.Gillnetfishermen in Ngrenehan lead to 35-40 people, trap fisherman are about 60- 100 people.While in 2009, trap fisherman in Baron approximately less than 10 people because of type of this gear is seasonal.This amount could be increase in peak season for example at the end of the year to the beginning of the following year.Statistic of Gunung Kidul District shown that the annual trip was likely decreased.in2O07, the trip was about 104 trips per unit while in 2008 about 77 trips per unit.seasonal characteristic tend to decrease the annual trip due to the low of annual fishing trip.
distribution of lobster sample, January to October 2009.