International Review of Hydrobiology Volume 70 Issue 4 1985 [Doi 10.1002%2Firoh.19850700406] Dr. L. I. Lebedeva; T. N. Gerasimova -- Peculiarities of Philodina Roseola (Ehrbg.) (Rotatoria,

8/12/2019 International Review of Hydrobiology Volume 70 Issue 4 1985 [Doi 10.1002%2Firoh.19850700406] Dr. L. I. Lebede

1/17

Int . Revueges. Hydrobiol. 70

1985 I 4 509-525

I;.I. LEBEDEVA

nd

T. N. GERASIMOVA

Department

of

Biology, Moscow St ate University, Moscow, an d Water Problems Ins ti tut e

of

the

Academy

of

Sciences

of

the

USSR,

Moscow,

USSR

Pcculiarities

of Philodina roseola (EHRBG.)

Rotatoria, Bdelloida)

Growth and Reproduction under Various Temperature Conditions

keg word f i :

rotifers, individnal culturing (ontogenesis), growth, reproduction, temper ature

Abstract,

JIost investigations dealing with rotifer reproduction have been performed with populations

and not n th individuals. At the same time the variations in the growth and reproduction rates

of rotifers are of considerable interest. This paper presents th e results of investigations carried

out by culturing individuals of Philodina

roseola.

during the lifespan of an individual under different

temperat ure conditions ranging from 9 to 35 "C. The paper presents curves showing the growth

in length a nd weight, the periods of maximum growth rate and t he maximum sizes of

Philodina

as affected by temperatu re conditions. The reproduction ra te is investigated a t th e same time.

The variation in egg evolution duration, in duration of the reproductive period and in th e egg

laying rate are shown under all th e conditions investigated. The da ta serve

as a

basis for estimating

the effect of temperature on the productivity of Philodina roseola.

Contents

1 . List

of

Symbols

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 509

2.

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

510

3. Materials and Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . .

510

4.

Results

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 511

4.1

Growth in length . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

511

4.2

Growt h in weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

514

4.3 Reproduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

517

5. Discnssion

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

521

6 . Conclusions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 523

7.

Suinniary

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

524

8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 524

9.

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 525

1 List of Symbols

t

C

temperatme, centigrades

t

time, days

or

hours

age of a n individual, days

length (weight) of the rotifer body a t age

t

(here and below

L

in

pin

and

W

(fresh weight) in mg

.

10-4)

initial length (weight) of the post-embryonic rotifer body

L W )

Lo(W , )


2/17

extreme lengt h (weight) achieved a t

'G -

(used in connection

witIl

Bertalanffy equation)

body width, pm

body volume

pm3

V =0 .47 bLL

V =

W ,

f

1

prn3= 10-9 nig raw weight

specific ra te of growth in length (weight)

of

an individual

absolute increase in weight (per da y)

relat ive increase in weight (per clay)

dura tion of egg developnient up to t he ~iionien t f hatching

age a t t he first laying (prereproductive period), hours

generation time;

D, D, D,

number of eggs

1 )

dou hling

tinie:

1

*2

=

dar

days

2 . Introduction

Rotifers are a n important element of freshwater ecosystems. They play an ou t-

standing role in th e substance an d energy cycles of water reservoirs. The rate

of

energy transforuiation a t this level an d the production level are largely determined by

such a n abiotic factor as temperature ( t o ) .

The aim

of

the study was to identify growth and reproduction pecularitiee of

Philodim roseola ( E H R B G . )

ithin the whole interval of biokinetic ten iperatures

during ontogenesis. According

t o

some authors

(LIPEROVSKAYA977, SCHAEFER

nd

PIPES

973),

the te mpe rature range of tolerance

for

Ph.

roseola

is

5-35'.

A t 38-40

C

rotifers die within 2-3 days.

3. Materials

and

Methods

The present investigation was carried out by individual cultivation, each specimen being

contained in 0.5 ml media

from

birth until death. The culture of

Ph. roseolu

was extracted

from

activated sludge a t aeration stations. Indiv iduals of

a

genetically homogeneous clone, th e offspring

of young females in subsequent generations were used for the exper iments, as young females in

their period of maximum fecundity give the most viable posterity (KING

967).

Rotifers were

adap ted to the following tempera tures during t he lifespan of

2-3

generations: go, 14 , 20 2 6 O 3 2 O

35

OC.

The culture media, prepared with water from

B

water supply, was renewed every day.

A week-old culture of ChZoreZZa vulgaris BEJER.with 3 pm cell diameter served

as

food for the

rotifers. I ts concentration was

11 . 106

cells per ml, or

0.16

mg of ra w algae weight per ml. The

average number of bacteria was 1.2-1.3

.

106 cells/ml. The relation of bright and dark period

during a day was 16 :

8,

the average illumination being 500 lux.

Each series started with 30 individuals; the number had decreased to

20

a t 32 OC. All in all,

140 amictic feniales of Ph.

roseola

were used

for

th e experiment. Each series was terminated u hen

all the individuals wcre dead.

During the experiment, L and b

of

each rotifer were measured

a t

the moment of

its

complete

stretching, while under

a

microscope with

7 ~ 1 0

agnification. When reproduction began, the

eggs were removed and counted.

In

addition,

De,

D, nd

t

were determined for each temperature

interval.


3/17

Philodina roseola under Various Tempera ture Conditions

51 1

4.

Results

4.1 Growth in

length

Values obtained by daily measurements served as a basis for plotting the curves of

the growth in length of Ph. roseola at the temperatures investigated. The hatching

time was taken as zero and t he size of a newly hatched rotifer ( 2 2 6 x 3 4

p i

as the

initial size. Hatching time is given with an accuracy of one hour. Figure

1

shows that

t

o c

La,

Pm

4 5 6 6

0

5 8 8

---x 2 6 5 8 8

3 2 5 2 0

- . - -A 3 5 4 1 L

e p r o d u c t i o n period

o. . . . . .o

200L I I I I > I , , , , , , , , ,

n

1

1 2 3

4 5 6

7

8

9 10 11 12 13 14

15 16

17 18 19

20 21 2 2 2 3

2 4 3 8 3 9 40

Individual length growth

L,

m)

of Philodinn roseola females

at

different tempers-

tures. The confidence band was calculated at the

95

'J/o level of significance.

A s e 171, dov5

Figure I.

the length of Ph.

roseola

changes greatly dur ing the organism's lifespan a nd tha t i t is

teni

p

eratu re dependent.

The growth in length of

Ph.

roseola a t the temperatures investigated and a t 20 C

(LEBEDEVAnd GERASIMOVA981) can be approximately described by the Berta-

lanffy equation as modified for growth in length (WINBERG966, MINA and KLXVEZAL

1976) :

Coefficient

k

was determined a t all temperatures from the minimal value of t he rela-

tive mean-square deviation

cr

Lt

=

L,- (L , L,)

. e - k t

(2)

(3

i = i


4/17

512

L. I

LEBEDEVA

nd

T. N. GERASIMOVA

L;=rotifer length measured on the ith d ay ;

L: =theoretic al rotifer length calciilated with the help of equa tion (2) ;

If=

number of measurements.

The values of

k

and

c

at. the different experiniental teinperatures were a s follows:

t "C l n

14 0.136 0.0494

20 0.412 0.0174

26

0.363 0.0540

32 0.630

0.0389

35

0.720

0.0270

These figures show that k increases as th e temperat,ure rises from 14

to

35

O. Equation

(2)

can be used to calculat,e

C L :

k

L,-Lo) e c k t

L,-(L,-L,)

e - k l

CL =

(4)

With the coefficient k and the known values of L,,and L, a t the experimental teni-

peratures, we can use equations

(2)

and (4) to calculate the size of a rotifer a t an y age

and the specific ra te of growth in length of Ph. roseolcc cultivated under similar

temperature and food conditions. Conversely, by analys ing the composition of na tura l

and laboratory populations of Ph. roseoln cultured under similar conditions, we can

estimate (with a certain approxiination) their age a nd growth rate.

To

perinit, analysis of the variat ions in the Philodina rate of growth in length during

their lifespan with the help

of

ernpirical da ta, t he value

CJ

was calculated for each age

using the-following equation :

In &-In L,

t , - - t1

C L =

( 5 )

where

t,--t, = 1

day, L, a nd L?= roti fer lengths (in

p i )

a t the beginning and th e end

of a day.

The most intensive growth (according to the C L value) was observed at all the

temperatures dur ing the first da ys of rotifer life. Figure

2

shows that one-day-old

rotifers had inaximum

C L

values for all tempe rature intervals (curve 1 . It is during

this period that the influence of tenipe rature on C L is inost evident. C L firs t increases

during the interval from

14

to 32C an d then decreases a t 35". During the second

day (curve

2)

the correlations of the growth rates under different t herma l conditions

change greatly. The sharp decrease in C L a t the investigated temperatures occurs a t

different times, hut always coincides with the beginning of reproduction. C, of breeding

females is not large and

is

practically constant.

It is known (BRODY945,

VASNETSOV

9 3 4 ) th at the growth rate of animals is

related not only

to

their age but also

to

the sizes they achieve. Figure

3

shows that

the

Philodinn

speciniens

260-320

pm long have the highest C L values, the height of

the peaks increasing as the temperatlurerises from

14

to

32 C.

The earlier the onset of

puberty, the sharper was the drop in the CL of th e specimens. The peculiarities of

rotifer growth a t the lowest 1 4 O ) and highest (35 "C) temperatures manifested theni-

selves in the fa ct th at the decrease in

C L

took place long before puber ty in relatively

sinall females

(260-270

p i ) an d is, we think,

an

indica tion of the oppressive influence

of these teniperatnres.


5/17

Philodina roseola under Various Temperature Conditions

513

0,6

-

(0

x

0.5

W

0.4

0 14

20

2 6 32 35

T e m p e r a t u r e

( CI

Figure 2. Specific rate of growth in length

C,) f

individuals of different age, depending on the

temperature, for the

0 0

irst,

0 - -.second,

v---v third,

@--.*-aourth,

0

a - U fifth,

B- sixth,

v .***..'*. v seventh day of life.

3200.

. .

.

.

. .

.

26'

x

t

o c

- 4

0

x--x 2 6

3 2

A . A

3 5

o.....o

eproduct ion

period

200 300 400 500 600

Leng t h (L), Prn

Figure

3.

Correlation between specific rate of growth in length

(C,)

and the average length of

an individual of

Philodina roseola

at different temperatures.

35

Int. Revue

ges.

Hydrobiol. 70 (1985)


6/17

514

L.

I

LEBEDEVA

nd T. N. GERASIMOVA

4.2.

Growth in weight

The investigation of facto rs governing growth in weight deserves special attent,ion

from the point of view of individual productivity estimation during ontogenesis, a s

growth in weight directly characterizes the magn itude of somatic production. Curves

showing the growth in weight of

Ph.

roseola

(Fig.

4)

were plotted on the basis

of

the

t ~ ~ r n g . 1 0 . ~

4

36.6

0 35.3

X--X 2 6 35.3

O . . . . . O

32 25.3

&...-A 35

ep roduc t i on per iod

8 . 2

I

I

,

, * ,

0

2

4

6

8 10 12

14

16 18

20 22 24

"35

Figure 4.

A g e

T I ,

days

Illdividual

weight

growth (W

f PhiZodina roseoZu a t different temperatures.

ineasureinents of individual leng th and width, t aking into account the nonproportion-

ality of female growth, with the help of equation

( I ).

The figure shows th at

Philoclina

weight growth

is

most intensive at 20" (except for the 10th and 22nd days a t 26

C).

This exception is due to t he fact th at a t

26

O reproduction is over by this time an d is

accompanied by a slight acceleration growth in feniale weight. The beginning of

reproduction is accompanied hy a decrease

in

the somatic growth rate under all

temperature conditions, a s the greater pa rt

of

the energy is spent on generative growth.

When reproduction is over, a certa in increase in the somatic growth rate is observed,

which stops after the extrem e weight is achieved. This increase is eviden t a t all the

temperatures except 35 C.

In order to analyse variations in the growth in weight of

Ph. roseola,,

the following

characteristics were calcnlated :

In W 2 - l n WI

t 2 - - t l

3w, ,v=

The results of these calculations for each 24-hour period are shown in Figures 5-8.

The value of the daily weight mass increase ( A

W )

dur ing th e lifespan varies consider-

ably (Fig.

5).

The general tendency of C w variations during th e ind ividual lifespan (Fig.

6)

mani-

fests itself in th e fact t ha t juvenile rotifers have the highest rates of growth in weight.

lndividua ls aged one or two days had the highest CW values. The only exception was


7/17

Philodina

roseola

under Various Temperature Conditions

lo/

il

0 i

14 20

26 3 2

35

Tempera tu re

1C)

515

Figure 5 .

0 0 first,,

a- . 0

third day, and

0 -.second,

Absolute daily increase in body weight

( AW )

f Philodina roseola individuals of different

ages a t different temperatures, for the

V .

v

th e average values for the whole period

of

growth.

a t

4 C.

A rapid decrease in the growth ra te a t 32-35" is associated mainly with

early puberty in

Ph. roseola

specimens. Hence, both low

1 4 O )

2nd high

(33-35

C )

temperatures inhibi t t he growth of young rotifers. This temperatures effect has dif-

ferent physiological causes, bu t the sanie "production consequences". When reproduc-

tion starts,

C w

decreases sharply a t all temperatures .

During the whole period of growth, the average daily C ~ Values increase as the

temperature rises. Figu re7 shows th at the average value of

C m

a t different ternperatu-

res

is

related t o the total duration of the growth period and decreases regularly a s the

dura tion of the growth period increases when th e tempera ture falls from

35

to 14

C.

This decrease is most abrup t in the temperatu re interval from

35

down to 26

C, b u t

is less severe in the int erval from 26 down to

14 C.

Figure

8

illus trates how the average daily CFvvalues vary with the weight and length

of growing rotifers clearly showing that specimens weighing up t o

10-4

nig had their

maximum

CW

values a t

26-35

C,

whereas larger individuals achieved their

Cjvmar

a t

temperatures of

14-20 C.

The

w

peak a t 14-20", which is fur the r towards the zone

of large

PItilodina

specimens, confirms the aforesaid regularity of Ph.

roseola

growth

a t high tempera tures, when the reduction in g rowth rate

is

connected mainly with the

onset

of

reproduction an d no t with the achieved size. Thus, rotifers weighing

8 - 1 0 ~

~ 1 0 - 4ng are already reproducing a t 26-32 C, whereas a t 14-20 C they are still

juveniles.

3.5'


8/17

516

L. I

LEBEDEVAnd

T. N.

GERASIMOVA

2

4 6 8 10 12 14 16

18

20

2::

? *

t o c

-

X--X

26

32

Documents

International Review of Hydrobiology Volume 70 Issue 4 1985 [Doi 10.1002%2Firoh.19850700406] Dr. L. I. Lebedeva; T. N. Gerasimova -- Peculiarities of Philodina Roseola (Ehrbg.) (Rotatoria,