Journal of the Persian Gulf (Marine Science)/Vol. 6/No. 19/March 2015/09/43-52
The Morphometric Variations of Freshwater Crab Sodhiana iranica from Southern Iran Sharifian, Sana*; Kamrani, Ehsan Department of Marine Biology, Faculty of Basic Sciences, Hormozgan University, Bandar Abbas, IR Iran Received: May 2014
Accepted: March 2015
© 2015 Journal of the Persian Gulf. All rights reserved.
Abstract Morphometric characters are important to estimate the population of crustacean species. In the present study, relationships between various morphometric characters of the freshwater crab Sodhiana iranica was studied at Eelood freshwater spring of southern Iran. Crabs were collected randomly from April 2012 to April 2013 bimonthly. A total of 69 (43.67%) females and 89 (56.32%) males were collected. Comparison of mean carapace width and total weight in both sexes showed no significant differences. The CL– CW relationship was CW=1.14 (CL) +1.23 for females, and CW=1.16(CL) +2.11 for males. The CW– TW relationship was TW=0.0003(CW) 3.01 for females, and TW=0.0003(CW) 2.98 for males. The CL– TW relationship was TW=0.0009(CL) 2.81 for females, and TW=0.0033(CL) 2.45 for males. The relationship between carapace width and weight for both sexes of S. iranica showed growth of crab is isometric. The result of this study showed that the morphometric relationships are essential for effective protecting of this crab in freshwater spring of Eelood area. Keywords: Freshwater crab; Morphometry; Southern Iran, Sodhiana iranica
et al., 2008). Freshwater crabs are one of the most ecologically important macro-invertebrate groups in tropical inland waters worldwide (Dobson et al., 2007; Yeo et al., 2008; Cumberlidge et al., 2009). They are excellent indicators of good water quality (Yeo et al., 2008) and play an important role in nutrient cycling in tropical freshwater ecosystems (Dobson et al., 2007). Freshwater crab Sodhiana iranica, is gecarcinid crab which has been reported only from Bastak, in southern Iran as a new species (Sharifian et al., 2014). The species inhabits a freshwater spring located in a semi-mountainous area in Iran (Eelood area), covered by dense stands of
1. Introduction About eighty percent of the 6800 species of brachyurans are marine species and the remaining dwell strictly in freshwater. It makes freshwater crabs the largest assemblage within the Brachyura, which in turn is the most species-rich of all decapod crustacean groups (Ng et al., 2008). True freshwater crabs are regarded as those that have adopted freshwater, semi-terrestrial or terrestrial modes of life, and are characterized by their ability to complete their life cycle outside the marine environment (Yeo *
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Sharifia an and Kamraani / The Morp phometric Varriations of Freesh water Cra ab Sodhiana…
deveelopmental pathways (Bagenaal, 1978).. Inforrmation ab bout indivvidual bod dy weight-lengtth/width relaationships in populations is importantt for estimating e th he populatioon size of a stock. Thee lengtth-width/weiight relationnships are regarded ass moree suitable fo or evaluatingg crustacean populationss (Gorrce et al., 200 06; Fumis ett al., 2007; Sangun et al.,, 2009 9; Josileen, 2011; 2 Sahoo et al., 2011; Oluwatoyinn et al.., 2013; Safaaie et al., 20113). In n the present study, relatiionships betw ween variouss morp phometric ch haracters, car arapace width h/length andd body y weight, len ngth and caraapace width of S. iranicaa are in nvestigated in n a populatioon from fresh hwater springg of Eeelood area, so outhern Iran.
com mmon reeds and salt cedar trees in the peripherry, witth mats of allgae on the bottom. b The crab c S. iranicca is the t fourth sppecies of Sodhhiana (Yeo and a Ng, 20122), and d is the secoond one known from Iraan. Among thhe nottable charactteristics of this t species one can nam me thee carapace being broaader than longer, l dorssal surrfaces smootth, tip of finger subspatu ulate, the maale firsst gonopodds with terrminal segm ment straighht, sub bconical, tipp directed uppwards, and female vulvaae rou unded, on aanterior half of sternite, with largge opercular cover (Sharifian et e al., 2014).. In crustaceeans, as groowth progresses, certaain mensions off the animal’s body may grow mucch dim mo ore than otthers, resultting in the phenomenoon known as relattive growth (Hartnoll, ( 19 974). Crabs, as thee most free -living crusttaceans, are ideal subjeccts forr morphomeetric studies because off the ease of tak king fast andd precise meeasurements on their haard exo oskeleton (L Ledesma et all., 2010). In studying crab species, measurin ng the lenggth craab is often soomewhat diffficult, and du uring attemppts to measure theem, either thhe extremitiees of the craab can n be broken or the investigator can be injured bby thee crab. It iss therefore convenient c to be able to con nvert into leength (width)), when only y the weight is known or llength-weighht regressio on may bbe mate length from weigght exttensively ussed to estim (Saangun et al.., 2009; Oluuwatoyin et al., 2013). In pop pulation studdies, morphoometric analy ysis providess a pow werful compplement to genetic g and environmenttal sto ock identificaation approaaches (Cadriin, 2000) annd len ngth-weight rrelationshipss allow the conversion of gro owth-in-lenggth equationss to growth--in-weight ffor usee in a stock assessment model (Mou utopoulos annd Steergiou, 20022). Knowledgge of these distinguishinng chaaracters andd size relattionships haave particullar im mportance in the study of valuablee crustaceanns. Su uch knowledgge can be usseful for furtther studies oon thee life historyy of species and a in the deevelopment of ressource manaagement. Stuudy of the length-weigght rellationship in aquatic anim mals has wide applicatioon in delineatingg the growtth patterns during theeir
2. Materials M and d Methods Th he sampling g area is thee freshwaterr springs inn Eelo ood area, Hormozgan proovince (27°1 13' N- 54°400 E) (Fig. ( 1).Thee climate oof zone is tropical. Inn fresh hwater sprin ngs of Eeloood, the pH is 7.99, thee salin nity 4 % and the annual w water temperrature variess from m 20 to 30°C.
Fig. 1: 1 Sampling locations in Eeloood Area, Hormo ozgan Province,, southern of Iran
Saamples weree taken from m April 2012 to Aprill 2013 3 every 2 mo onths (due too the low nu umber of thee specimens and risk of loss re serves). Specimens weree colleected random mly by hannd. Entire sample wass placeed inside thee plastic galllons of ice contains, c andd transsferred to thee laboratory. 44
Journal of tthe Persian Gulf G (Marine Science)/Vol. S 66/No. 19/Marcch 2015/09/433-52
In the labboratory, craabs were iden ntified and ssexed. The carapacce width (CW W) and caraapace length (CL) was measuured using a vernier caliper (±0.055 mm accuracy), teerminology is i based on Ng N (1988) (Fiigure. 2). The totaal body weigght (TW) weere measuredd in a standard ellectric balannce (LA310 0S model) with 0.0001g acccuracy. Thhe overall size s and w weight frequency distributions were testeed for norm mality Kolmogorov Smirnov (L Lilliefors) (D D) test using the K (Zar, 1999).. The mean size s of males and females were compared using the Studdent t-test. Th he mean weigght of males and females weere compared using thee non m size of both b sexes dduring parameteric-test. The mean o AN NOVA different moonths were teested using one-way followed byy Tukey’s poost-hoc test. The mean w weight of both sexxes during different d mo onths were ttested using Non--parametric test follow wed by Kruuskal– Wallis testt. Mean ± standard errror is pressented through the text. The annalysis of ressults was donne by SPSS 19 andd Excel softw wares.
If the valuee b be equal or close to 3, 3 the growthh of sp pecies is isom metric, and iff the value b had h distancess of 3, then growth h is allometriic. This form mula is knownn as wn as allomeetric alllometric forrmula and b also is know co oefficient (Cadima, 2003)). A linear eq quation (log W W= log a + b log CW) was w fiitted to the logtransform med data. Deviation D of the esstimated ‘b’ value from tthe isometricc value of 3 was w teested using t test: =
×
−3 √1 −
2
×√ −2
d of the where SD (CW) is thee standard deviation lo og CW valuees, and SD (w w) the standaard deviationn of th he log W values, n beingg the numbeer of crabs used u in n the computtation. The vvalue b is diffferent from 3 if t is greater than t the tablle value of t for n - 2 df Pauly, 1983). (P 3. Results A total off 158 crabs were colleccted during the sttudy: 89 maales (56.3%)), and 69 females (43.6%). Comparison C of o mean caraapace width (CW) ( and mean to otal weight (TW) in both sexess revealed no siignificant diifferences (t--test, p>0.05 5). Comparison of mean carap pace width ((CW) (ANOVA, F = 27..32; p < 0.05) an nd mean tottal weight (T TW) (χ2 (5) = 69.12; p < 0.05 0 during different months m show wed
Fig. 2: Overall dorsal view of male m (30.2 × 23.1 mm), Bastak, Iran
siignificant diffferences.
The CW––CL relationsship was estim mated in eachh sex, from the lineear equation of o y= a+bx where, y is the carapacee width in mm m x is the caraapace length in mm, ‘a’ and ‘b’ aare constantss. The CW W–TW and CL–TW reelationships were estimated aaccording to the formulaa W= aLb (ppauly, 1983) where, W is the total weiight in mg an nd o the carapaace in mm L is the lenggth or width of a is the interrcept (condition factor) and b is the slope (growtth coefficientt).
3.1 Morphom metric charactteristics 3.1.1. Length--width relatioonship Length-wid dth relationshhip (CL-CW W) for 69 fem male hiana iranicaa is represen nted in Tablle 1 crrabs of sodh an nd Figure 3.. There was a high correelation between caarapace leng gth and widthh (R2= 0.97) (p
