Oreochromis niloticus niloticus L. L. Oreochromis Melodina D. D. - - PowerPoint PPT Presentation

Effects of Delayed First Feeding Effects of Delayed First Feeding

• n the Development of the
• n the Development of the

Digestive Tract and Skeletal Digestive Tract and Skeletal Muscles of Nile Tilapia, Muscles of Nile Tilapia, Oreochromis Oreochromis niloticus niloticus L. L.

Melodina Melodina D.

• D. Fabillo

Fabillo* , Annabelle A. Herrera, Ph.D.* * , Jose S. * , Annabelle A. Herrera, Ph.D.* * , Jose S. Abucay Abucay* * * , Ph.D * * * , Ph.D. .

* University of the Philippines in the * University of the Philippines in the Visayas Visayas Tacloban Tacloban College College * * University of the Philippines, * * University of the Philippines, Diliman Diliman, , Quezon Quezon City City * * * Freshwater Aquaculture Center, College of Fisheries, Central * * * Freshwater Aquaculture Center, College of Fisheries, Central Luzon State University Luzon State University

I NTRODUCTI ON I NTRODUCTI ON

During the last half century, fish farmers throughout the tropical and semi-tropical world have begun farming tilapia. Today, more than 90% of all commercially farmed tilapia are Nile tilapia, Oreochromis niloticus

• L. (Popma and Masser, 1999).

I NTRODUCTI ON I NTRODUCTI ON

Second to milkfish, tilapia now ranks as the most important cultured fish in the Philippines (Guerrero, 1994). Tilapia farming is not only associated with its potential as a source of food, but also as an attractive source of investment (Bimbao and Smith, 1988).

I NTRODUCTI ON

I n a NATURAL ENVI RONMENT where predators abound, female tilapias delay the release

• f their fry for protection.

I n COMMERCI AL HATCHERI ES, delay in first feeding occurs when farmers fail to notice that the fry had already totally absorbed their yolk and are ready to receive exogenous food.

OBJECTI VES OF THE OBJECTI VES OF THE STUDY STUDY

To trace the development To trace the development

• f the digestive tract and
• f the digestive tract and

skeletal muscles of Nile skeletal muscles of Nile tilapia, tilapia, O.

• O. niloticus

niloticus L. from

• L. from

0-

• 150 days post

150 days post-

• feeding

feeding when first feeding is when first feeding is delayed delayed

SI GNI FI CANCE OF SI GNI FI CANCE OF THE STUDY THE STUDY

essential to the understanding

• f whether the development
• f certain organs in nile tilapia

larvae is most vulnerable during starvation allows tilapia farmers to decide the cost effectiveness

• f rearing previously starved

fry up to their marketable size

MATERI ALS AND MATERI ALS AND METHODS METHODS

Egg incubation and rearing of larvae Egg incubation and rearing of larvae – – 1 month 1 month Preliminary testing Preliminary testing – – 10 days 10 days Starvation and feeding experiments Starvation and feeding experiments – – 5 months 5 months Histology Histology Light Microscopy Light Microscopy Statistical analysis Statistical analysis Electron Microscopy Electron Microscopy (SEM and TEM) (SEM and TEM)

BREEDI NG AND REARI NG OF BREEDI NG AND REARI NG OF FRY OR LARVAE FRY OR LARVAE

X X

XX XX YY YY

XY XY

Genetically male tilapia (GMT) Genetically male tilapia (GMT)

PRE PRE-

• TRI AL EXPERI MENT

TRI AL EXPERI MENT

200 fry 200 fry 200 fry

1st batch – one parental source 2nd batch – one parental source Starved until total mortality was

• bserved

Actual Experimentation

ACTUAL EXPERI MENTATI ON ACTUAL EXPERI MENTATI ON

1000 fry were used 1000 fry were used

T1 (control): fed immediately after yolk absorption

T2: starved for 2 days T3: starved for 4 days T4: starved for 6 days T5: starved for 8 days 200 200 200 200 200

sampling stocking in “hapas” sampling

2 days 2 days

sampling 4, 6, 8, 20, 30, 60, 90, 150 days 4, 6, 8, 20, 30, 60, 90, 150 days

SAMPLI NG SAMPLI NG

14 14 14 14 14 14 14 14 14 14 Day 150 Day 150 5 5 5 5 5 5 5 5 5 5 Day 120 Day 120 5 5 5 5 5 5 5 5 5 5 Day 90 Day 90 5 5 5 5 5 5 5 5 5 5 Day 60 Day 60 5 5 5 5 5 5 5 5 5 5 Day 30 Day 30 5 5 5 5 5 5 5 5 5 5 Day 20 Day 20 5 5 5 5 5 5 5 5 5 5 Day 8 Day 8 5 5 5 5 5 5 5 5 5 5 Day 6 Day 6 5 5 5 5 5 5 5 5 5 5 Day 4 Day 4 5 5 5 5 5 5 5 5 5 5 Day 2 Day 2 5 5 5 5 5 5 5 5 5 5 Day 0 Day 0 T5 T5-

• starved

starved 8 days 8 days T4 T4-

• starved

starved 6 days 6 days T3 T3-

• starved

starved 4 days 4 days T2 T2-

• starved

starved 2 days 2 days

T1 T1(control)

(control)

5 samples 5 samples – – histology histology 3 samples 3 samples– – SEM SEM 3 samples 3 samples– – TEM TEM 3 samples 3 samples -

• histochemistry

histochemistry

LI GHT MI CROSCOPY LI GHT MI CROSCOPY

Dehydrated in alcohol series, mounted in glass slides Dehydrated in alcohol series, mounted in glass slides

PURPOSE: to trace the development of the PURPOSE: to trace the development of the skeletal muscles and organs of the digestive skeletal muscles and organs of the digestive tract from day 0 (day of hatching) to day 150 tract from day 0 (day of hatching) to day 150 (adult marketable size). (adult marketable size).

EMPHASI S EMPHASI S

Pancreas Pancreas Esophagus Esophagus

Skeletal Muscles Skeletal Muscles – – diameter diameter

• f muscle fibers (
• f muscle fibers (µ

µm) m) Liver Liver – – diameter of hepatic portal

diameter of hepatic portal vein vein (

(µ µm) m) Anterior and posterior Anterior and posterior intestine intestine -

• height of mucosal fold

height of mucosal fold Height of Height of muscularis muscularis layer layer (

(µ µm) m)

Number of goblet cells Number of goblet cells

Stomach Stomach –

– height of mucosal fold

height of mucosal fold Height of Height of muscularis muscularis layer layer (

(µ µm) m)

TISSUE TISSUE

TRANSMI SSI ON ELECTRON TRANSMI SSI ON ELECTRON MI CROSCOPY MI CROSCOPY

Processing Processing

PURPOSE: to trace the development PURPOSE: to trace the development

• f the cells in the anterior intestine
• f the cells in the anterior intestine
• f the adult marketable fish (day
• f the adult marketable fish (day

150). 150).

SCANNI NG ELECTRON SCANNI NG ELECTRON

Tissue processing Tissue processing

PURPOSE: to examine the surface features of the anterior intestine of the adult marketable fish (day 150).

STATI STI CAL ANALYSI S STATI STI CAL ANALYSI S

• Data were presented as means

Data were presented as means ± ± standard error. standard error.

• Means were tested using Analysis of

Means were tested using Analysis of Variance (ANOVA) followed by Variance (ANOVA) followed by Duncan’s Multiple Range Test Duncan’s Multiple Range Test (DMRT). (DMRT).

• Analyses were performed using

Analyses were performed using Statistical Analysis Software (SAS). Statistical Analysis Software (SAS).

RESULTS AND DI SCUSSI ON

RESULTS RESULTS

Figure 1. Comparison of the effect of delayed first feeding on the weight (grams) of 0-150 dph unstarved and starved O. niloticus . 5 10 15 20 4 8 30 90 150 age (dph) of fish weight (grams) unstarved 2 days starved 4 days starved 6 days starved 8 days starved

Figure 2. Comparison of the effect of delayed first feeding on the length (centimeters) of 0-150 dph unstarved and starved O. niloticus samples. 2 4 6 8 10 4 8 3 9 1 5 age (dph) of fish length (centimeters) unstarved 2 days starved 4 days starved 6 days starved 8 days starved

Figure 3. Comparison of the effect of delayed first feeding on the gut length (centimeters) of 30-150 dph unstarved and starved O. niloticus samples.

20 40 60 80 30 60 90 120 150 age (dph) 0f fish gut length (cm)

unstarved 2 days starved 4 days starved 6 days starved 8 days starved

STARVATI ON STARVATI ON

To deprive the nile tilapia fry of exogenous food, notwithstanding their readiness, is a form of STARVATION, which delayed their growth and development for lack of basic nutrients. This deprivation is a type of STRESS that

• rganisms often encounter in nature

(www.biol.unt.edu.,2004). Many pathological changes occur in a starved animal: decrease in size and weight; atrophy in the musculature; digestive tract becomes empty.

METHODS USED TO STUDY METHODS USED TO STUDY STARVATI ON I N FI SH STARVATI ON I N FI SH

Morphological, histological or biochemical Morphological measurements have the advantages of ease and practicality of application as an indicator of starvation (Dou et al., 2002). For this study, however, it was helpful to also use histological examination of tissues during starvation to validate the practicality and applicability of the morphological indicators used.

• Fig. 4. Cross
• Fig. 4. Cross-
• section of the anterior abdominal cavity of 6

section of the anterior abdominal cavity of 6 days post days post-

• hatch (

hatch (dph dph) Nile Tilapia, 100X. ) Nile Tilapia, 100X.

Unstar ved Unstar ved star ved star ved

star ved star ved

• Fig. 5. Cross
• Fig. 5. Cross-
• section of the esophagus, stomach, and

section of the esophagus, stomach, and intestine of an 8 intestine of an 8 dph dph starved Nile Tilapia, 100X. starved Nile Tilapia, 100X.

• Fig. 6. Cross
• Fig. 6. Cross-
• section of the anterior intestine of 6

section of the anterior intestine of 6 dph dph Nile Tilapia, X1000. Nile Tilapia, X1000.

unstar ved unstar ved star ved star ved

unstar ved unstar ved star ved star ved F

• ig. 7. Cr
• ss

F

• ig. 7. Cr
• ss-
• sec tion of the anter

ior intestine of the 120 sec tion of the anter ior intestine of the 120 dph dph Nile tilapia, X1000. Nile tilapia, X1000.

F

• ig. 8. T

r ansmission elec tr

• n mic r
• gr

aph of the anter ior F

• ig. 8. T

r ansmission elec tr

• n mic r
• gr

aph of the anter ior intestine of the 150 intestine of the 150 dph dph Nile T ilapia, X21,600. Nile T ilapia, X21,600. unstar ved unstar ved star ved star ved

GOBLET CELLS GOBLET CELLS

The talent of goblet cells is to secrete mucus. The talent of goblet cells is to secrete mucus.

F unc tions of Muc us Cells: F unc tions of Muc us Cells:

• pr
• tec tion against shear

str ess and pr

• tec tion against shear

str ess and c hemic al damage c hemic al damage

• tr

apping and elimination of tr apping and elimination of par tic ulate matter and mic r

• or

ganisms. par tic ulate matter and mic r

• or

ganisms.

GOBLET CELLS GOBLET CELLS

T he abundant muc ous gr anules seen in the T he abundant muc ous gr anules seen in the unstar ved unstar ved fish may not be due to a higher fish may not be due to a higher ac tivity in ter ms of func tions mentioned; ac tivity in ter ms of func tions mentioned; instead, it may be attr ibuted to the instead, it may be attr ibuted to the abundanc e of r aw mater ials pr esent for its abundanc e of r aw mater ials pr esent for its for mation. for mation.

F

• ig. 9. Sc anning elec tr
• n mic r
• gr

aphs of the anter ior F

• ig. 9. Sc anning elec tr
• n mic r
• gr

aphs of the anter ior intestine of 150 intestine of 150 dph dph Nile T ilapia, X3000. Nile T ilapia, X3000. unstar ved unstar ved star ved star ved

unstar ved unstar ved star ved star ved F

• ig. 10. Cr
• ss

F

• ig. 10. Cr
• ss-
• sec tion of the poster

ior intestine of 6 sec tion of the poster ior intestine of 6 dph dph Nile T ilapia, X1000. Nile T ilapia, X1000.

F

• ig. 13. Cr
• ss

F

• ig. 13. Cr
• ss-
• sec tion of the skeletal musc le of the 120

sec tion of the skeletal musc le of the 120 dph dph Nile T ilapia, X1000. Nile T ilapia, X1000. unstar ved unstar ved star ved star ved

F

• ig. 14. Sc anning elec tr
• n mic r
• gr

aph of the longitudinal F

• ig. 14. Sc anning elec tr
• n mic r
• gr

aph of the longitudinal sec tion of the 150 sec tion of the 150 dph dph Nile T ilapia, X10,000. Nile T ilapia, X10,000. unstar ved unstar ved star ved star ved

What then might have caused the signif icant What then might have caused the signif icant dif f erences in total weight and length dif f erences in total weight and length between between unstarved unstarved and starved f ish? and starved f ish?

Recent findings: Recent findings: Delayed development or smaller size of the following Delayed development or smaller size of the following in starved fish were observed: in starved fish were observed:

1. 1.

Kidney and testis ( Kidney and testis (Badulis Badulis, R.J., A.A. Herrera and , R.J., A.A. Herrera and M.D. Fabillo, 2004) M.D. Fabillo, 2004)

2. 2.

Cardiovascular system (Cruz, J., A.A. Herrera Cardiovascular system (Cruz, J., A.A. Herrera and M.D. Fabillo, 2004) and M.D. Fabillo, 2004)

3. 3.

Immune system ( Immune system (Tiongco Tiongco, A.T., A.A. Herrera and , A.T., A.A. Herrera and M.D. Fabillo, 2004) M.D. Fabillo, 2004)

4. 4.

Skin and skeletal system Skin and skeletal system – – thinner adipose thinner adipose tissue in hypodermis ( tissue in hypodermis (Somejo Somejo, M., A.A. Herrera , M., A.A. Herrera and M.D. Fabillo, 2004) and M.D. Fabillo, 2004)

CONCLUSI ONS CONCLUSI ONS

Delay in initial feeding has inhibitory effect on the total length and weight of the 30 dph until mature marketable fish (150 dph). The most statistically significant result was observed in the fish starved for 8 days before initial feeding.

CONCLUSI ONS CONCLUSI ONS

Histological measurements used for this study, did not show any statistically significant difference between the unstarved and starved fish, except the abundance of goblet cells in the unstarved fish which was higher than those found in the starved fish aged 90-150 dph.

CONCLUSI ONS CONCLUSI ONS

Skeletal muscle TEM and SEM analyses showed that there were no

• bservable differences

between unstarved and starved fish.

RECOMMENDATI ONS RECOMMENDATI ONS

It may be useful to study It may be useful to study several hormones, such several hormones, such as growth and thyroid as growth and thyroid hormones, in relation to hormones, in relation to delay in first feeding. delay in first feeding.