Effect of temperature and salinity on respiratory rate and development of early larval stages of Macrobrachium acanthurus (Wiegmann, 1836) (Decapoda, Palaemonidae)

Camp. Biochem. Physiol. Vol. 118A, No. 3, pp. 871-876, 1997 Copyright 0 1997 Elsevier Science Inc. All rights reserved.

ISSN 0300-9629/97/$17.00 PII SO300-9629(97)00016-9

ELSEVIER

Effect of Temperature and Salinity on Respiratory Rate and Development of Early Larval Stages of Macrobrachium acanthurus (Wiegmann, 1836) (Decapoda, Palaemonidae) D. Ismael and

G . S.

Moreira

DEPARTAMENTO DE FISIOLOGIA, INSTITUTO DE BIOCI~NCIAS, C.P. 11461, UNIVERSIDADE DE Sdo PAULO, CEP 05422-970 Sbo PAULO, BRASIL

ABSTRACT.

Macrobrachium

acanthurw

larvae

were reared

(0, 7, 14, 21, 28 and 35%0S at 15, 20, 25 and 30°C). I, II, III and IV. The oxygen

consumption

at different

Th e survival

rates were measured

salinity

and temperature

and respiratory

at 25°C

combinations

rate were measured

in all tested

salinities,

using

for zoea a Warburg

respirometer. Larvae reared in fresh water died at stage I in all tested temperatures. The highest survival rates were obtained at 25 and 30°C within a range of 14-21%cS. Th e metabolic rate-salinity (M-S) curves for all zoeae studied showed lower values either in 14 (zoeae II and III) or 21%& (zoeae I and IV). However, values were not significantly different for zoeae III and IV, which showed to be more salinity independent. COMP BIOCHEM PHYSIOL 118A;3:871-876, 1997. 0 1997 Elsevier Science Inc.

KEY WORDS. Crustacea, ration,

salinity,

survival,

crustacean

larvae,

freshwater

INTRODUCTION

This

America, West

species

is distributed

from Georgia

Indies

Choudhury

(U.S.A.)

in the to southern

eastern

part

of

Brazil and the

(8). (4), working

with animals

from Jamaica,

suc-

cessfully reared the larvae through all stages to juveniles and described the morphology of the larval stages. The same author

(5) described

larvae vival

and analyzed time

the methods the effects

and moulting

to 27°C. This author

of its larval life. Although for aquaculture purposes,

development;

needs therefore,

of salinity

rearing

of

from

that this palaemonid

23

shrimp

this species is of great significance very little is known about its physbrackish

ucanthurus,

Palaemonidae,

respi-

water

the ovigerous

to complete female

larval

migrates

to

time. From egg eclosion until the larvae undergoes 11-12

From the first to the fifth moult,

instar,

but after the sixth

moult,

develop-

ment becomes irregular and each moult does not always result in a new instar (4). Moreira et al. (14,15), working with specimens

from southern

Brazil, studied

the effects

of salin-

ity on the respiratory rates of the first zoea and adults on hemolymph osmotic concentrations in adults. The present

study examines

the effects

of different

combinations

on larval

survival

perature-salinity metabolic

responses

to a wide range

of selected

and

and temthe

stages of larval development

of salinities.

and diet on survarying

species for commercial culture, conshort duration and high survival rate

the estuarine zone at hatching metamorphosis into juveniles, moults.

for laboratory

at temperatures

suggests

appears to be a suitable sidering the reasonably

iology. M. ac&thurus

Mucrobrachium

in a new larval

Macrobrachium acunthurus is a palaemonid shrimp very common in most rivers of the coast of the State of Sso Paulo, Brazil.

shrimp,

temperature

each moult

results

Address reprint requests to: G. S. Moreira, Departamento de Fisiologia, Instituto de BiocGncias, C.P. 11461, U mversidade de SBo Paula, CEP 05422970 SBO Paula, Brasil. Fax (0055) 11-818-7416. Received 4 July 1996; accepted 18 December 1996.

MATERIALS Ovigerous

AND METHODS

females

of th& freshwater

shrimp

M. acanthurus

were collected from the Guaec6 river, located on the northern coast of the State of Sgo Paula, Brazil (ca. 23”49’S: 45”27’W), were kept

during 1987 and 1988. In the laboratory, females in small aquaria containing aerated fresh water

and fed with fish. The

larvae

usually

hatched

in the early evening.

They

were collected by using a pipette, after being induced to concentrate in one corner of the aquarium where there was a shaft 35%&)

of light. The were prepared

rearing media (0, 7, 14, 21, 28 and with filtered Guaec6 beach seawater

diluted with GuaecA River fresh water. The very active larvae were placed in glass culture dishes with 80 ml of fresh filtered salinity.

medium and divided into groups of 10 for each They were kept in constant temperature cham-

872

Ll Ismael

and G. S. Moreira

hers at 15, 20, 25 and 30°C under a photo regime of 12-hr light: 12-hr dark. Three replicates were used for each salinity-temperature

combination.

The

shrimp

larvae

were fed

with newly hatched brine shrimp nauplii Artemia salina (a. 10 nauplii/ml), and the water in the bowls was changed daily. Larvae were reared from zoea I to zoea IV, and records of survival and moulting were taken daily. Larval instars were identified

according

The survival opmental

stage, being

isms that moulted the duration mean

to Choudhury

percentage

(4).

was determined

established

for each devel-

as the percent

to the next instar.

of each instar were statistically

and SD of moulting

of organ-

The survival

data and

analyzed

cycle duration

(days)

using

for each

developmental stage (zoea I to zoea IV) for the 24 combinations of temperature and salinity. To examine

respiratory

metabolism,

a Warburg

eter (21) was used. Larvae were reared of 7, 14,21,28 were placed

respirom-

at 25°C in salinities

and 35%0. For the experiments, in each 5-ml flask, depending

20-35

zoeae

on larval size, for

each of the salinities in which they were reared. The oxygen consumption was measured in larvae to the C-D0 stage of the moulting readings

were taken every 15 min over a period

30 min at 25°C. Six replicates

close

cycle. The manometric

were done

of 1 hr and

for each salinity.

To determine the dry weight, the larvae of each flask were rinsed in distilled water, dried for about 24 hr at 6O”C, placed

in a desiccator

for 2 hr and then weighed

Gram

electrobalance

(0.1 pg sensitivity).

on a Cahn

Results

are ex-

pressed as ,ul oxygen consumed/mg dry weight/hr. The significant differences between means of oxygen consumption

data

were calculated

and Student-Newman-Keuls

using a one-way (SNK)

method

4

ANOVA

(24).

8

12

I6

20 24 TIME

4 (days)

12

16

20

24

FIG. 1. The effect of salinity on survival and larval develop ment of Macrobnwhium acanthurus at 15 and 20°C. I, first zoea; II, second zoea; III, third zoea; IV, fourth zoea.

RESULTS Larval Development The

combined

effects

of salinity

and temperature

on sur-

vival and duration of the larval stage are presented in Figs 1 and 2. All larvae reared in fresh water died at stage 1 without moulting in all temperatures in which they were reared.

At 15”C, only 63.3%

and 13.3% of those

of the larvae reared

in 35%oS moulted

The larvae reared at 20°C reached 7 to 35%;

however,

the survival

in 14%&

to the second

stage IV in salinities rate was low. The

stage.

of the first larval stage is 5.9,4.4

and 3.5 days, respectively.

The moult intervals had the tendency to increase as the larvae developed in all temperature-salinity combinations.

from best

survival for the zoea IV at this temperature was in 21%& (56.6Oh). A very high survival rate was obtained at 25°C in higher salinities (14-35%&). Maximum survival of zoea IV took place in 21%& (96.9%). Figure 2 shows that larvae reared at 30°C exhibit high survival in the first and second stages in low salinities. In 28 and 35%& mortality occurs from stage I on, although during larvae development, mortality is less pronounced than that obtained in low salinities. Temperature had an accentuated effect on moulting cycle duration required

for example, the mean duration of the stage I is IO.7 days. At 20, 25 and 30°C in the same salinity, the mean duration

(Tables l-3). High temperature reduces the time to reach the next larval stage. At 15°C and 14%&,

Respiration

Table 4 shows the effect of salinity

on the oxygen

consump-

tion rate by the zoeal stages of M. acunthurus. In salinity of 7%0, there is a significant increase in the metabolic rate from zoea I to zoea III (zoea IV did not survive in this salinity). In salinity of 14%0, zoeal stages did not vary their oxygen consumption very much, although a significant lower respiration rate was obtained for zoea II when compared with zoea IV. In salinity of 21%0, values were not different for zoea II, III, and IV, but a lower value was obtained for zoea I. In salinities of 28 and 35%0, there were no significant

Larval Development of M. acunthurus

873

differences due to the stage of development

(at 0.05 signifi-

cance level). Table 4 also shows the effect of salinity for each of the larval stages. Zoea I showed a significantly higher metabolic rate in 28 and 35%&

when compared with results obtained

in 7, 14 and 21%0, which are similar. Zoea II showed a broadly U-shaped metabolic-salinity curve, with a significant lower value in the salinity of 14”A. Values obtained for the respiration of zoea III and IV showed a high level of metabolic nificantly),

salinity independence

(data did not vary sig-

although values obtained

in salinities of either

14 or 21%0 were slightly lower than the others.

DISCUSSION

M. acunthurus adults live in fresh and brackish water, exhibiting great osmoregulatory

capability.

found that the hemolymph

osmotic

Moreira

et al. (15)

concentration

of M.

acanthurus adult females is maintained constant in salinities from 0 to 7%0, showing hyperosmotic regulatory capability. However, from 7 to 35%oS, the hemolymph osmotic concentration

increases with that of the medium but only re-

mains hypo-osmotic

in salinities above 21%0. The isosmotic

point is reached at 22.4%& (640 mOsm). These authors also demonstrated that mortality occurs at 35%& during a period of 24 hr. The present study shows that M. acunthurus larvae are able to develop in a wide range of salinity, although they do not survive more than 5-6 4

8

12 I6 20

24

4

8

12 16 20

24

and M. carcinus are well adapted to fresh water, but the best salinity ranges for larvae rearing in the laboratory were 15-20 and 14-17’%S, respectively. Although M. curcinus larvae are adapted to a middle range of salinity, the adults have already achieved success in fresh water (9). The same may occur for the M.

TIME (days) FIG. 2. The effect of salinity on survival and larval develop mentof Macrobrachiumacanthurus at 25 and 30”C.I,6rst zoea; II, second zoea; III, third zoea; IV, fourth zoea.

TABLE

1. Effect of salinity and temperature

days in fresh water. Choud-

hury (5,6) showed that M. acanthurus

on first moult of Macmbmchium

acanthums larvae

Salinity (%o)

Temwrature (“0 15 PM DCM VOM 20 PM DCM VOM 25 PM DCM VOM 30 PM DCM VOM PM, moult

0

7

14

21

28

35

63.3 10.7 2 0.9 10-14

-

-

-

percentage;

13.3 9.0 2 0 9-10

100 6.3 + 0.7 6-8

100 5.9 2 0.9 5-9

6.3 2 1.1 6-11

100 4.4 2 0.5 5-7

100 4.4 * 0.5 5-6

4.6 t- 0.5 5-7

100

100 3.5 2 0.5 4-5

3.3 -e 0.4 4-5

3.3 t 0.4 4-5

DCM, mean duration of moulting cycle (days) + standard deviation;

96.6 5.8 -+ 0.7 6-9

6.6*: 0.4 7-8

100

100 4.8 + 0.5 5-7

96.6 4.9 2 0.5 4-6

100

96.6 3.3 z 0.4 4-5

86.6 3.3 -+ 0.4 4-5

100

VOM, variation on moult occurrence

(days).

874

D. lsmael and G. S. More&a

TABLE

2. Effect of salinity and temperature

on second moult of Macrobrachium

acanthurus larvae

Salinity (%0) Temperature

0

(“C)

7

15 PM DCM VOM 20 PM DCM VOM 25 PM I?CM VOM 30 PM DCM VOM

21

14

KM,

50.0 12.3 i 1.5 12-16

73.1 12.2 ? 0.3 12-16

63.3 12.2 2 0.6 12-16

63.3 I2 2 0.6 17-13

43.3 12.6 ? 1.1 12-15

HO 9.9 t 1.1 9-12

9i 8.C) t 0.7 U-11

96.6 10.2 +- 1.4 9-13

93.3 10.3 2 0.9 IO-13

90 49.0 i 1.2 8-13

100 6.8 t 1.1 6-9

96.6 6.7 -+ 0.9 6-l)

100 6.4 2 1.1 6-Y

mean duratkm of mwlting

TABLE 3. Effect of salinity and temperature

cycle (days) -t au&d

clewat~~~n; VOM, varnnon

on third moult of Macrobrachium Salinity

Temperature

0

(“C)

percentage;

DCM, me,m duratum

TABLE 4. Respiratory rate (,ul OJmg

Arithmetic

mean 2 standard

(days).

(%O) 28

35

40 16.7 + 1.1 16-19

2.3 17.2 i- 1.8 16-20

13.3

16.6 16.0 2 0.7 16-18

56.6 16.7 -+ I 16-19

36.6 13.4 ? 1.1 13-16

95 12.9 ? i\.s 11-15

96.6 13.7 t 1.1 13-17

$6.6 14 f 0.9 13-17

‘10 12.9 2 1.1 12-15

93.3 X.8 ? 0.7 9-11

93.3 8.7 ? 0.8 H-17

96.6 8.4 i- 0.6 9-11

86.6 8.4 i- 0.5 9-10

HO 8.4 + 0.6 o-11

cycle (days) + ~tandrd

dry weightlhr)

dcvlation;

of Macrobrachium

14

7

devintl~~n; II = 6.

occurrence

83.3 6.8 k 0.9 6-9

16.5 ? 1.9 16-20

t,f mwlting

3.67 2 1.01 5.65 + 1.20 5.17 + 1.07

1 11 III IV

on mwlt

21

4.50 3.24 4.07 5.85

i ? k k

VOM, variation

on mtulr recurrence

(%,)

21 0.90 0.65 1.4-i 1.65

3.62 4.11 5.x 4.02

(days).

acanthurus larvae in different salinities at 25°C

Salinity Larval stage

90 6.5 2 1 6-9

acanthurus larvae

14

7

15 PM DCM VOM 20 PM DCM VOM 25 PM DCM VOM 30 PM DCM VOM

Zoea Zoea Zoea Zoea

35

-

PM, tnoult percentage;

PM, mtdt

28

i 0.89 -+ 0.30 t 1.05 + 1.59

28 5.66: 5.31 4.38 5.07

t 0.75 ? 1.3’1 i 0.68 t- 1.00

35 5.13 4.66 4.49 4.36

C t 5 i-

0.60

0.48 0.64 1.14

Larval Development

of M. ucanrhurus

acanthurus species. The close dependence of these larvae to a saline medium and the large number of larval stages suggest that this species may be a recent migrant to the limnic environment. Our results show that salinity affects the larval development of M. acanthurus; however, the effect depends on the temperature. The first zoea can stand a wide range of salinity at 20-30°C. During the development process, the larvae become less tolerant to salinity. The early stages of M . ucunthumsand M .curcinus are also euryhalines but become more stenohalines during larval development (516). The effects of salinity and temperature on survival of Palaemonetes vulgaris larvae were studied by Sandifer (19). This author found poor survival of zoea I and II in 5%& but a high survival rate in salinities from 20 to 30%0 at temperatures from 20 to 30°C. Zoeae I and II of M. holthuisis also showed poor survival in low salinities (O-7%0); however, different from P. vulgaris, they also showed poor survival in high salinities (21%0) at temperatures of 15-35°C (13). According to McNamara et al. (12), these results may reflect the distribution of the adult animal (i.e., M. holthuisi and M. acanthurus live in fresh water, whereas P. vulgaris live in brackish water). The osmoregulatory capacity of Mucrobrachium petersi larvae was studied by Read (18). He found that zoeae I hyperosmoregulate in fresh water, this capability being lost by zoea II-IV and then recovered by postlarvae. Hence, the inability of zoea II-IV to osmoregulate in fresh water is effective to confine these larvae to estuaries. Our results suggest that zoeae I of M. acunthurus are also able to hyperosmoregulate in fresh water, surviving for 5-6 days, although they do not moult in this medium. Although the effect of salinity is not very clear, the increase of temperature, within a tolerance range, results in an acceleration of the development. Clibanmius vittatus larvae were reared at 20 different salinity-temperature combinations (23). At 15”C, the larvae do not develop, although at 20-35”C, development occurs, although partially. The temperature also has a marked effect on the development rate of Pagurus criniticomis larvae, so that increasing this parameter decreases the time required to complete each larval stage and consequently that to attain the first crab stage (2). In the present study, M. acanthurus larvae reared at 15°C do not develop. Passano ( 17) studied the effect of temperature on the premoult stage of Uca pugnax, applying eyestalk ablation techniques. The premoult duration is shorter between 29 and 32”C, and at low temperatures the time interval increases significantly. The beginning of premoult is sensitive to temperature and becomes blocked at 15°C or lower. The survival rate and larval development of M. acanthurus are affected by both parameters, zoeae I and II being, however, more euryhaline than III and IV. Crustaceans show a variety of physiological changes that

875

affect the respiratory rate of the animal when exposed to salinity alterations (22). Moreira et al. (14) studied the effects of acute exposure to salinity on the metabolic rates of the first zoeal stages of palaemonid shrimps. They suggest that Mucrolrrachium species may be divided into two groups that may possibly reflect different osmoregulatory mechanisms. The first group would comprise M. acanthurus and M. olfersii zoea I, which show an increase in metabolic rates in concentrated and/or diluted salinities. This pattern is commonly encountered in euryhaline invertebrates ( 11). The second group would consist of M. heterochirus and M. carcinus larvae, which exhibit an apparent tendency to decrease metabolic rates in both high and low salinities. We found that M. ucanthurw larvae reared in different salinities show a pattern of oxygen consumption throughout the developmental sequence, similar to that reported in experiments of acute salinity effects on zoea I respiration (14). The metabolic-salinity rate curves obtained in the present work for zoea I-IV showed lowest values in either 14 or 21%0 salinity, but there was a tendency to be more salinity independent as they become older. We assume that those metabolic rate differences might reflect functional and structural changes that occur during larval development. Physiological changes accompanying the developmental process were reported by Stephenson and Knight (20) on comparing the oxygen consumption data of M. rosenbergii postlarvae with those of juveniles (16). The metabolic-salinity rate curve of M. acanthurus adult females (15) is very different from that of zoea I (14) and zoea I-IV presented in this study. The same fact occurs for M. olfersii adults and the first-stage zoea (14,15). Although the metabolic-salinity zoeae I and II curves of M. acanthurus show a U shape, in adults there is a small variation of respiratory rates in salinities from 0 to 14%0S, the curve then assuming a dome shape with a high peak close to the isosmotic point. The osmoregulatory control of decapod crustacean adults is associated to the X-organ/sinus gland process, the pericardial and supra esophagial organ and the thoracic ganglion. The evidence of neuroendocrine control for larvae osmoregulatory responses include ablation of eyestalk experiments of, for example, Homarus americanus (3) and Rhithropanopeus hawissii larvae (10). In Palaemon sewutus, the sinus gland was reported from stage V and the X-organ is present just after metamorphosis (1). Dalla Via (7), studied the effect of salinity on the oxygen consumption of Pduemonetes antenna&s adults. He found that this freshwater shrimp shows the lowest consumption at the isosmotic point, even when the metabolic rate increased, the osmotic work representing a small percentage of energy expenditure. Tentative swimming activity as an escape mechanism from a stressed salinity environment was responsible for the increase of oxygen consumption. Thus, although the adult metabolic-salinity curve cannot be explained only in terms of osmotic work, certainly in the lar-

876

D. Ismael and G. S. Moreira

val forms, high energy

expenditure

might be directly

ated to maintenance of the osmotic gradient. Some larvae that exhibit metabolic rate independent on salinity as Mac-

robmchium heterochirus might and/or

to water

osmoregulation

movement

the stage. These larvae

survival

conditions, present ture.

use little

9.

to ionic energy

for

10.

(12).

The data of oxygen show the lowest

be less permeable or might

Palaemoninae.

associ-

value results,

consumption

obtained

in 14 and/or

21%&,

linked

on

to the fact that the highest

rates were obtained

in these

suggest that it is in this salinity

the best development

in our study depending

with

Il. 12.

same salinity

range that larvae

lower energy

expendi-

This research was supported by the “Conselho Naciond de Desenoolvimento Cient$co e Tecnol&gico (CNPq).” We me very grateful also to the staff of the CEBIMAR (Centro dr Biologia M&&-LISP) for their valuable help in the field.

Ii.

14.

Ii.

References 1 Bellon-Humhert, C.; Thijsxm, M.J.; Van Herp, F. L)evclopment. locarion and relocation of sensory and neurosecretoq site5 in the eyestalks during the larval and poxlarval life c)t Pa&non serrut~s (Pennant). J. Mar. Ri(~l. Assoc. UK 58:85 1~ 868;1978. etfects ot remper+ 2. Blaazkowski, C.; Moreira, G.S. Comhmed ture and salinity on the aurvlval and duraticm <)f larval stage> of Pagwtts criniticomis (Dana) (Crusracca. Paguridae). J. Exp. 81,,1. Ecol. 103:77-86;1986. G.; Charmantier-Daures. M.; Aiken, D.E. Neu3. Charmantier, roendocrine control of hydromineral regulation in the Amcrlcan lobster Homarus americanus H. Milnr-Edwards, 1837 (Crustacea; L>ecapoda). 2. Larval and post-larval stage\. Gcn. Camp. Endocrinol. 54:20-34;1984. P.C. Complete larval development of rhe p&c4. Choudhury, monid shrimp Macrolrrachium acanthurrtr (Wiegmann, 1836) reared in the laboratory (Decapoda, Palameonidae). Crustacedna 18:113-132;1970. P.C. Lah~xxt~q~ rearing crf larvae of the palae5. Choudhury, monid shrimp Macrohmchium ctcanrhurus (Wiegmann, 1836). Crustaceana 21:113-126:1971. P.C. Responses c~f larval Macrobrachium ~‘arcmus 6. Choudhury, (L.) to variations in salinity and diet (Decapoda, Palarm~>nidae). Crustaceana 2@:113-120;1971. Dalla Via, G.J. Effects of salinity and temperature on oxygen consumption in a freshwater populatmn of Palaemonrtcs ante,]narius (Crustacea, Decapoda). Camp. Biochem. Physiol. 88A: 299-305;1987. Holthuis, L.B. A general revision of the Palaemonidae (Crustacea, Decapoda, Natantia) of the Americas. II. The sub&ily

Los Angeles: Allan Hancock Foundation; 1952:1-296. (Occasional paper) Hubschman, J.H. Larval development of the freshwater shrimp Palaemonetes kadiakensis Rathbun, under osmotic stress. Physiol. Zool. 48:97-104;1975. Kalber, F.A.; Costlow, J.D., Jr. The ontogeny of osmoregulation and its neurosecretory control in the decapod crustacean Rhitropanopeus harrisii (Gould). Am. Zool. 6:221-229;1966. Kinne, 0. Salinity: Invertebrates. In: Kinne, 0. (ed). Marine Ecology, Vol. 1. London: Wiley; 1971:821-995. McNamara, J.; Moreira, G.S.; Souza, S.C.R. The effect of salinity on respiratory metabolism in selected ontogenetic stages c,f the freshwater shrimp Macrobrachium olfersii (Decapoda, Palaemonidae). Camp. B’IOCh em. Physiol. 83A:359-363; 1986. Moreira, G.S.; McNamara, F.C.; Moreira, P.S. The combined effects of temperature and salinity on the survival and moultlng c~fearly zoeae of Macrobrachium holthuisi (L)ecapoda, Palaemonidae). Bol. Fisiol. Anim. 3:81-93;1979. Moreira, G.S.; McNamara, F.C.; Moreira, P.S. The effect of salinity on the metabolic rates cd some Palaemonid shrimp larvae. Aquaculture 29:95-100;1982. Moreira, G.S.; McNamara, F.C.; Shumway. S.E.; Moreira, P.S. Osmoregulation and respiratory metabolism in Brazilian MacP a 1,aemonidae). *Ijhrachium (Decapoda, Camp. Biochem. Physiol. 74A:57-82;1983. Ncl.\on, S.G.; Armstnmg, D.A.; Knighr, A.W.; Lit, H.W. The effect> ttf temperature and x~linity on the metabolic cxw c>i juvenile Macrohrachium ro.senEergii (Crustacea: PalaemoniJae). Camp. Biochem. Physiol. 56A:533-537;1977, Passano, L.M. Low temperature blockage of moulting m L’ca pugncc.x. Biol. Bull. Mar. Biol. Lab. 118:129-l 36;196@. Read, G.H.L. Intrasprcitic variation in the osmoregulnt~~ry capxity cd larval, postlarval, juvcnlle and adult Mncrohuchium [)eter.si (Hilgrndorf). Corny. Biochem. Physiol. 78A:5L7 I-506; 1984. Sandifer, P.A. Effects of rempcrxurc and salinity on lar\xl dcvvlopment of gr”sh shrimp Puklemonetes ed,pris (L)ecapoda, Cariduc). Fish. Bull. 7l:l 15-124;1973. Stephenson, M.!.; Knight, A.W. tin)wrh, respiration and cnI(iric content of larvae of the prawn, Macrohachium tnsenbqhii. Comp. Biochem. Phyaiol. 66A:385-191;1980. Umbreir, W.W.; Burris, R.H.; Stanffer. J.F. Manomrtric ,rnd filochemical Techniques. 5th Ed. Minnesota: Burgess Publishinp Co.; 1972. Vcrnherg, F.J. Respirntory adaptation. In: Vernberg, F.J.; Vernherg, W.B. (eds). Biology of Crustacea, Vol. 8. New York: Academic Press; 1983:1-33. Young, A.M.; Hazletr, T.L. The effect ofsalinity and temperature on the larval development of Clibunarius vittatus (Bust) (Crustacea, Decapoda, Dioyenidae). J. Exp. Mar. Biol. Ecol. 34:131-141;1978. Zar, J.H. Biosratistical Atlalys~s. New Jersey: f’rentice Hall Inc.; 1974.