Development & Reproduction
The Korean Society of Developmental Biology
ARTICLE

Effects of Starvation in Rock Bream, Oplegnathus fasciatus and Olive Flounder, Paralichthys olivaceus

In-Seok Park1,†, Hyun Woo Gil1, Gwang Yeol Yoo2, Ji Su Oh1
1Division of Marine Bioscience, College of Ocean Science and Technology, Korea Maritime and Ocean University, Busan 606-791, Korea
2The Province of Chungcheongnam-do Fisheries Research Institute, Boryeng 355-851, Korea
Corresponding author : In-Seok Park, Division of Marine Bioscience, College of Ocean Science and Technology, Korea Maritime and Ocean University, Busan 606-791, Korea. Tel. : +82-51-410-4321, Fax : +82-51-405-4322, ispark@kmou.ac.kr

Copyright © 2014 © The Korean Society of Developmental Biology, All rights reserved. This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Received: May 11, 2015 ; Revised: May 28, 2015 ; Accepted: Jun 9, 2015

ABSTRACT

We assessed the effects of various dietary conditions on the growth, phenotypic traits, and morphometric dimensions of rock bream, Oplegnathus fasciatus and on the morphometric dimensions of sectioned olive flounder, Paralichthys olivaceus. Rock bream in the fed group increased in body weight, standard length, and condition factor, but these parameters decreased significantly for fish in the starved group (P < 0.05). The head connection dimensions of fish in the fed group decreased, while for starved fish there was increase in external morphometric dimensions (P < 0.05). In both species, sectioned morphometric analysis revealed that fish in the fed group had a larger body circumference and cross-cut sectional area, and greater cross-cut section height, relative to the starved group (P < 0.05).


INTRODUCTION

Many species of fish undergo periods of natural starvation because of temperature declines associated with seasonal changes, spawning migration, and regional and seasonal decreases in food supply. To survive periods of starvation fish use biochemical, physiological, and behavioral strategies, in addition to using stored endogenous energy derived from basic metabolic processes (Mustafa & Mittal, 1982; Weatherley & Gill, 1987; Lee et al., 1999; Park et al., 2002, 2007; Hur et al., 2006a, 2006b; Park, 2006). However, this survival strategy leaves little energy for other biological functions, including somatic growth. As a result, growth in body size slows considerably during starvation. From a commercial perspective, traits including size, weight and sectioned body parameters are important because they control the value of the product (Gjerde, 1989; Gjerde & Schaeffer, 1989; Park et al., 2002).

Although the body shape of fish is largely determined by genetic factors (Riddell et al., 1981; Taylor & McPhail, 1985), the use of morphometric analysis to discriminate among genetically discrete groups within a single fish species is limited by the difficulty of measuring environmentally induced variations in body shape (Ihssen et al., 1981; Currens et al., 1989; Park et al., 2001). Consequently, understanding how morphometric characteristics are affected by various feeding regimens will improve assessment of genetically discrete groups within the same species in habitats where food abundance and quality differ (Currens et al., 1989).

Both truss and classical dimensions are used to describe fish body shape (Hubbs & Lagler, 1947; Straler, 1947). Truss dimensions, which include components of body depth and length along the longitudinal axis, have theoretical advantages over classical morphometric characters in discriminating among groups (Humphries et al., 1981; Straüss & Bookstein, 1982; Winans, 1984; Currens et al., 1989). A variety of characteristics of the sectioned surface are critical elements in the marketing of fish because of consumer preferences with respect to the size and shape of the sectioned surface in gutted, sectioned, smoked, and non-gutted fish (Gjerde, 1989; Gjerde & Schaeffer, 1989; Park et al., 2002).

Rock bream, Oplegnathus fasciatus, is a marine fish that occurs in rocky areas of shallow coastal regions, and is distributed in these habitats in the marine environments of Korea, Japan, Taiwan, and Hawaii (Choi et al., 2002). To meet the demand for this high-quality popular fish in Korea rock bream are raised in aquaculture facilities along the south coast at Tongyeong, Geoje, Namhae, and Yeosu. As suggested by its flattened oval body, olive flounder, Paralichthys olivaceus, is a bottom dwelling fish; it mainly occurs on the benthos at depths of 10–20 m. The species is widely distributed in Korea and East Asia (Choi et al., 2002). The olive flounder has a flattened oval body, and mainly occurs in the benthos at depths of 10 to 200 m, with a wide distribution in Korea and East Asia. Approximately 40,922 tonnes of this species were produced in Korea in 2010 (Park et al., 2012). The olive flounder may experience shortor long-term starvation, e.g., directly when feeding is arrested, or indirectly because of low water temperatures when cold water masses move into their habitat or during red tides in the warm summer season in Korea (Park et al., 2012).

In previous study of rock bream’s starvation, effects of starvation on kidney melano-macrophage centre in subadult and growth and development of larval and juvenile have been reported (Seol et al., 2009; Sun et al., 2009).

The effects of starvation on growth, phenotypic traits, morphometric characteristics and histological change of hepatocyte and intestinal epithelium in olive flounder have been reported (Park, 2006; Park et al., 2006, 2007). But similar studies between olive flounder and rock bream have not been undertaken. Therefore, in this study we investigated the effects of starvation on growth, phenotypic traits and morphometric characteristics in rock bream, and also determined the effects of starvation on sectioned morphometric characteristics in both olive flounder and rock bream.

MATERIALS AND METHODS

1 Experimental fish

In July 2011, specimens of rock bream, Oplegnathus fasciatus (SL, standard length±SD: 15.86±0.75 cm; BW, body weight±SD: 164.7±32.21 g), and olive flounder, Paralichthys olivaceus (SL±SD: 16.6±0.45 cm; BW±SD: 100.7±11.67 g), were obtained from the Gyeongsangnam-do Fisheries Resources Research Institute, Korea. The fish were transported to the Fishery Genetics and Breeding Science Laboratory of the Korea Maritime University, Korea, and reared in a recirculating culture system. Feeding and starvation experiments began in July 2011 (rock bream) and October 2011 (olive flounder), and were terminated after eight and twelve weeks, respectively, when the fish began to exhibit obvious distress from fasting.

Three experimental groups were established; initial control, fed and starved. For two weeks prior to commencement of each experiment the fish were fed daily with commercial feed (E-Wha Oil & Fat Ind. Co. Ltd, Busan, Korea; 50% crude protein, 8% crude fat, 4% crude fiber and 15% ash) at a rate of 1–3% of total BW. During the experiment the fed group was hand-fed three times daily at 4 h feeding intervals, while the starved group was fasted throughout the experiment. The experiments were conducted in a recirculating system consisting of 1.1 ton FRP circular tank (118 cm diameter × 100 cm depth). Each experimental treatment comprised two tanks, each containing 40 specimens. Light was provided by four 40W fluorescent bulbs controlled by an electric timer, which maintained a 12 h:12 h light:dark cycle. No lights were used during the dark period. The water temperature was controlled automatically, and maintained at 22±0.6°C during the experimental period.

2 Investigation of growth and phenotypic traits

For the rock bream, 10 fish were removed from the fed and starved groups, respectively, and used for growth measurements and assessment of phenotypic traits. The SL and BW of each fish was measured to the nearest 0.01 cm using a digital vernier caliper (CD-20CP, Japan), and the BW of each fish was measured to the nearest 0.01 g using an electronic balance (JW-1, Korea). Fish were euthanized with an overdose of clove oil (Sigma, USA). The growth and phenotypic factors examined included growth rate for standard length (GRL), growth rate for body weight (GRW), SL, condition factor (CF), un-gutted BW, gutted body weight (GW), viscera weight (VW), viscera index (VI), and dressing percentage (DP).

3 External morphometric analysis

For rock bream 20 fish were removed from the fed and starved groups for external morphometric analysis. The fish were euthanized with an overdose of clove oil and the length of each fish was measured as described above. Body outline measurements between landmarks were made for both truss (20 distances) and classical (11 distances) dimensions (Fig. 1 and Table 1). Each morphometric dimension was analyzed relative to the SL.

Table 1. Body shape dimensions in rock bream, Oplegnathus fasciatus
Dimension
Truss dimension
Posterior end of supraocciptal - origin of dorsal fin 1×2
Posterior end of supraocciptal - origin of pelvic fin 1×8
Posterior end of supraocciptal - origin of pectoral fin 1×9
Posterior end of supraocciptal - posterior end of maxillary 1×10
Origin of dorsal fin - insertion of dorsal fin 2×3
Origin of dorsal fin - origin of anal fin 2×7
Origin of dorsal fin - origin of pelvic fin 2×8
Origin of dorsal fin - origin of pectoral fin 2×9
Insertion of dorsal fin - dorsal origin of caudal fin 3×4
Insertion of dorsal fin - ventral origin of caudal fin 3×5
Insertion of dorsal fin - insertion of anal fin 3×6
Insertion of dorsal fin - origin of anal fin 3×7
Insertion of dorsal fin - origin of pelvic fin 3×8
Dorsal origin of caudal fin - ventral origin of caudal fin 4×5
Dorsal origin of caudal fin - insertion of anal fin 4×6
Ventral origin of caudal fin - insertion of anal fin 5×6
Insertion of anal fin - origin of anal fin 6×7
Origin of anal fin - origin of pelvic fin 7×8
Origin of pelvic fin - origin of pectoral fin 8×9
Origin of pectoral fin - posterior end of maxillary 9×10
Classical dimension
Most anterior extension of the head - posterior end of supraoccipital 1×2
Most anterior extension of the head - origin of dorsal fin 1×3
Most anterior extension of the head - dorsal origin of caudal fin 1×5
Most anterior extension of the head - insertion of anal fin 1×7
Most anterior extension of the head - origin of anal fin 1×8
Most anterior extension of the head - origin of pelvic fin 1×9
Most anterior extension of the head - origin of pectoral fin 1×10
Most anterior extension of the head - posterior end of maxillary 1×11
Most anterior extension of the head - most posterior aspect of operculum 1×12
Insertion of dorsal fin - most posterior scale in lateral line 4×6
Insertion of anal fin - most posterior scale in lateral line 6×7

Refer to landmarks of Fig. 1 for number of Table 1.

Download Excel Table
dr-19-2-97-g001
Fig. 1. Truss and classical dimensions for rock bream, Oplegnathus fasciatus in this starvation experiment. The morphological landmarks are numbered and the morphometric distances between landmarks are shown: (a) truss dimension; (b) classical dimension. SL, standard length.
Download Origianl Figure
4 Sectioned morphometric analysis

For each of rock bream and olive flounder, a morphometric analysis of body sections was undertaken based on 10 and 30 fish sampled from the fed and starved groups, respectively. The experiment was carried out in triplicate. The length of each species was also measured to the nearest 0.01 cm using a digital vernier caliper (CD-20CP, Japan), and to the nearest 0.1 cm using an opisometer (Curvimeter, Japan). The width of each fish was measured using the grid method.

Fish were captured, euthanized with an overdose of clove oil (Sigma, USA), and sectioned along the O, A, and M lines shown in Figs. 2 and 3. The body morphometric dimensions examined (Figs. 2 and 3) were CIA (the circumference of the body at a right angle from the midpoint of the SL), CIO (the body circumference at one-third of the distance between the most posterior point of the operculum and the midpoint of the SL), CIM (the body circumference midway between the midpoint of the SL and the most posterior scale on the lateral line), AO (the area at one-third the distance between the most posterior point of the operculum and midpoint of the SL), AA (the area at a vertical line that intersects at right angles to the midpoint of the SL), AM (the area at the midpoint between the midpoint of the SL and most posterior scale on the lateral line), THO (the total height at one-third distance between the most posterior point of the operculum and the midpoint of the SL), THA (the total height at a vertical line intersecting at a right angle to the midpoint of the SL), THM (the total height at the midpoint between the midpoint of the SL and most posterior scale on the lateral line), WO (the width at one-third distance between the most posterior point of the operculum and the midpoint of the SL), WA (the width at a vertical line that intersect at a right angle with the midpoint of the SL), WM (the width at the midpoint between the midpoint of the SL and most posterior scale on the lateral line), HO (the height at one-third distance between the most posterior point of the operculum and the midpoint of the SL), BTO 1 (belly thickness 1 at one-third distance between the most posterior point of the operculum and the midpoint of the SL), BTO 2 (belly thickness 2 at one-third distance between the most posterior point of the operculum and the midpoint of the SL), ABT (average belly thickness), BS (body shape), SS (section shape), Ratio 1 (fed/initial), Ratio 2 (starved/initial), and Ratio 3 (fed/starved).

dr-19-2-97-g002
Fig. 2. Total height (THX), width (WX), area (AX), height (HO), and belly thickness (BTO1 and BTO2) in rock bream, Oplegnathus fasciatus, measured on cross sectional slices made at one-third of the distance between the most posterior point of the operculum and the midpoint of the standard length (X=O), at a vertical line that intersects at a right angle with the midpoint of the standard length (X=A), and at a line at the midpoint between the midpoint of the standard length and most posterior scale on the lateral line (X=M).
Download Origianl Figure
dr-19-2-97-g003
Fig. 3. Total height (THX), width (WX), area (AX), height (HO), and belly thickness (BTO1 and BTO2) in olive flounder, Paralichthys olivaceus, measured on cross sectional slices made at one-third of the distance between the most posterior point of the operculum and the midpoint of the standard length (X=O), at a vertical line that intersects at a right angle with the midpoint of the standard length (X=A), and at a line at the midpoint between the midpoint of the standard length and most posterior scale on the lateral line (X=M).
Download Origianl Figure
5 Statistical analysis

All experiments were performed in triplicate. The data were analyzed by one-way ANOVA using the SPSS statistical package (SPSS 9.0; SPSS Inc., USA). Means were separated using Duncan’s multiple range test and were considered significantly different at P < 0.05 (Duncan, 1955).

RESULTS

Table 2 shows the growth measurements and phenotypic traits for the fed and starved groups of rock bream, Oplegnathus fasciatus. The values for GRL and GRW were higher in the fed group than in the starved group (P < 0.05). For CF, all three groups (fed, starved, and initial) were significantly different from each other (P < 0.05). The fed group was 1.15-fold that of the initial group, the starved group was 0.85-fold that of the initial group, and the fed group was 1.66-fold that of the starved group (P < 0.05). The values of GW, VW, and VI were highest for the fed group, and for DP were highest for the starved group (P < 0.05).

Table 2. Phenotypic traits of rock bream, Oplegnathus fasciatus after 8 weeks in initial, fed, and starved treatments
Trait Initial group Fed group Starved group Ratio 1 Ratio 2 Ratio 3
SL (cm) 15.9± 0.76a 16.9± 1.72a 13.5±1.16b 1.06 0.85 1.25
BW (g) 164.7±32.21b 231.2±57.34a 086.1±19.67c 1.40 0.52 2.69
GRL (%) - 6.9±11.39a -15.1± 6.17b - - -
GRW (%) - 46.0± 5.13a -46.7±11.38b - - -
CF 4.1± 0.71b 4.7± 0.50a 3.5±0.27c 1.15 0.85 1.34
GW (g) 139.3±28.17b 193.2± 5.28a 85.2±9.23c 1.39 0.61 2.27
VW (g) 17.0± 6.87b 27.9± 7.33a 5.8±1.15c 1.64 0.34 4.81
VI (%) 11.8± 3.24b 14.7± 2.26a 6.9±1.02c 1.25 0.58 2.13
DP (%) 8 9.5± 2.58b 87.2± 1.67c 93.6±0.89a 0.97 1.05 0.93

The values are means SD (n=10) of triplicate groups. In each row the means with the same superscript letter are not significantly different (P > 0.05). Abbreviation, SL: standard length; BW: body weight; GRL (growth rate for standard length; %): (final mean SL-initial mean SL)×100/initial mean SL; GRW (growth rate for BW; %): (final mean BW-initial mean BW)×100/initial mean BW; CF: condition factor=un-gutted BW×100/standard length; GW: gutted body weight; VW: viscera weight; VI: viscera index=(viscera weight/GW)×100; DP: dressing percentage=(GW/un-gutted BW)×100; Ratio 1: fed group/initial group; Ratio 2: starved group/initial group; Ratio 3: fed group/starved group.

Download Excel Table

As shown in Table 3, the results of measurement of external morphometric dimensions for the fed and starved groups of rock bream revealed. There were significant differences in the truss dimensions between the fed and starved groups (P < 0.05). Relative to the initial group, for the fed group the values of 1×2 and 3×8 increased but those of 3×4 and 4×6 decreased, while for the starved group the values of 1×2, 1×9, 1×10, 4×5, 4×6, and 5×6 increased but those of 3×8 and 7×8 decreased (P < 0.05). There were no significant differences among the three feeding regimes for the truss dimensions 1×8, 2×3, 2×7, 2×8, 2×9, 3×5, 3×6, 3×7, and 6×7 (P > 0.05). Significant differences were also found in the classical dimensions between the fed and starved groups (P < 0.05). Relative to the initial group, the values of 1×5 and 1×9 decreased in the fed group, whereas in the starved group the values of 1×2, 1×3, 1×5, 1×10, and 1×12 increased but that of 4×6 decreased (P < 0.05). The classical dimensions 1×7, 1×8, 1×11, and 6×7, did not differ significantly among the three feeding regimes (P > 0.05).

Table 3. Truss and classical dimensions of rock bream, Oplegnathus fasciatus after 8 weeks in initial, fed, and starved treatments
Dimension Initial group Fed group Starved group
Truss dimension
1×2 18.8±1.56b 20.2±1.39ab 20.8±2.08a
1×8 45.3±1.88a 45.7±2.23a 46.9±1.68a
1×9 27.9±1.32b 28.4±1.80b 29.9±1.29a
1×10 22.6±1.01b 22.6±1.66b 24.5±1.98a
2×3 58.6±2.40a 58.3±2.34a 59.1±1.50a
2×7 64.4±3.39a 63.7±2.89a 65.7±2.63a
2×8 50.3±2.65a 50.9±2.15a 51.2±2.06a
2×9 34.2±2.44a 34.6±1.75a 34.7±1.34a
3×4 11.6±0.99a 9.0±0.84b 11.9±1.20a
3×5 17.0±1.07a 17.0±1.42a 17.6±0.69a
3×6 15.6±0.65a 16.1±0.95a 15.7±0.82a
3×7 38.1±1.13a 39.0±1.63a 38.9±1.85a
3×8 57.1±1.15b 60.0±2.59a 54.9±2.23c
4×5 15.1±0.99b 14.3±1.18b 16.6±0.87a
4×6 18.9±1.50b 17.5±1.51c 20.5±1.25a
5×6 8.9±0.77b 8.7±0.74b 10.0±0.79a
6×7 26.2±1.74a 26.6±2.56a 26.6±1.54a
7×8 30.7±1.42a 31.0±1.93a 27.5±2.50b
8×9 18.8±0.90ab 19.6±0.95a 18.2±1.14b
9×10 23.9±1.12ab 23.4±1.32b 25.4±2.33a
Classical dimension
1×2 23.1±0.90ab 22.1±2.45b 24.6±2.25a
1×3 40.9±2.73b 42.2±2.40b 45.0±2.55a
1×5 96.1±1.65b 94.3±1.96c 97.8±1.25a
1×7 87.6±3.54a 86.3±3.39a 87.3±3.02a
1×8 70.7±2.49a 68.4±3.34a 70.1±2.93a
1×9 43.8±1.80a 40.6±2.49b 43.9±2.11a
1×10 30.7±1.08b 29.7±1.70b 32.4±1.58a
1×11 8.7±0.56a 8.3±1.14a 8.4±0.82a
1×12 32.2±1.42b 32.7±1.56b 34.8±1.72a
4×6 17.1±1.01a 16.1±1.72ab 15.5±1.12b
6×7 16.7±1.34a 16.8±0.98a 16.8±0.92a

The values are means±SD (n=20) of triplicate groups. In each row the means with the same superscript letter are not significantly different (P > 0.05). Refer to the landmarks in Fig. 1 and Table 1 for the dimension numbers in Table 3.

Download Excel Table

Table 4 shows the morphometric measurements of the sectioned bodies of the fed and starved groups of rock bream and olive flounder, Paralichthys olivaceus. In rock bream the dimensions CIO, CIM, AO, AA, AM, THM, and WA increased in the fed group relative to the initial group, and no significant decrease was found for any morphometric dimension (P < 0.05). For the starved group the SS 2-1 dimension was significantly higher than in the initial and fed groups, but the values of most of the other dimensions in the starved group were significantly lower (P < 0.05). There were no significant differences among the three groups for the dimensions BS 1, BS 2, SS 3-1, SS 3-2, SS 3-3, and SS 4-1 (P > 0.05).

Table 4. Sectioned body characteristics of rock bream, Oplegnathus fasciatus, and olive flounder, Paralichthys olivaceus initial, fed and starved for 8 weeks
Dimension Initial group Fed group Starved group Ratio 1 Ratio 2 Ratio 3
Rock bream
SL (cm) 16.5±0.18a 17.6±0.48a 12.9±1.59b 1.06 0.78 1.36
CIO (cm) 18.9±0.83b 20.9±0.84a 14.5±1.15c 1.11 0.77 1.44
CIA (cm) 18.9±0.70a 20.4±0.82a 13.8±0.85b 1.08 0.73 1.47
CIM (cm) 15.5±1.24b 18.1±1.25a 12.2±0.82c 1.17 0.79 1.48
AO (cm2) 10.9±0.81b 14.4±0.89a 5.1±0.47c 1.32 0.47 2.80
AA (cm2) 11.4±0.97b 16.8±1.16a 5.2±0.14c 1.47 0.45 3.24
AM (cm2) 7.1±0.62b 11.3±0.96a 3.3±0.20c 1.61 0.46 3.47
THO (cm) 8.1±0.08a 9.0±0.76a 6.6±0.47b 1.11 0.81 1.37
THA (cm) 8.3±0.41a 9.0±0.54a 6.5±0.54b 1.09 0.78 1.39
THM (cm) 7.4±0.50b 8.5±0.65a 5.9±0.45c 1.16 0.80 1.45
HO (cm) 3.2±0.06a 3.6±0.48a 2.6±0.17b 1.11 0.81 1.36
WO (cm) 2.7±0.04a 3.0±0.32a 1.6±0.18b 1.12 0.59 1.90
WA (cm) 2.5±0.14b 2.9±0.18a 1.4±0.16c 1.13 0.53 2.12
WM (cm) 1.8±0.29a 2.2±0.22a 0.9±0.05b 1.24 0.49 2.54
BTO 1 (cm) 0.3±0.06a 0.4±0.07a 0.2±0.02b 1.31 0.66 2.00
BTO 2 (cm) 0.2±0.03a 0.2±0.02a 0.1±0.03b 1.17 0.70 1.66
ABT (cm) 0.3±0.04a 0.3±0.04a 0.2±0.02b 1.26 0.67 1.87
BS 1 114.4±4.44a 116.2±1.54a 107.8±9.79a 1.02 0.94 1.08
BS 2 50.1±2.63a 51.2±1.72a 50.4±4.21a 1.02 1.01 1.02
BS 3 15.4±0.99a 16.4±1.31a 10.7±2.29b 1.06 0.69 1.54
SS 1-1 33.1±0.50a 33.4±2.64a 24.1±1.88b 1.01 0.73 1.39
SS 1-2 30.8±2.43a 32.1±3.52a 21.2±4.04b 1.04 0.69 1.52
SS 2-1 120.0±1.07b 118.8±8.79b 166.9±8.93a 0.99 1.39 0.71
SS 3-1 9.4±1.18a 10.9±2.57a 11.0±2.40a 1.15 1.16 0.99
SS 3-2 12.2±2.05a 14.7±3.80a 13.8±1.96a 1.20 1.13 1.06
SS 3-3 6.7±0.99a 7.1±1.46a 8.2±3.02a 1.06 1.23 0.86
SS 4-1 63.1±5.17a 58.8±11.54a 64.5±12.60a 0.93 1.02 0.91
Olive flounder
SL (cm) 16.6±0.45c 28.7±0.99a 18.7±0.95b 1.72 1.12 1.53
CIO (cm) 12.8±0.26c 24.1±0.81a 14.1±0.84b 1.88 1.10 1.71
CIA (cm) 12.9±0.24c 24.8±0.71a 14.1±0.84b 1.93 1.10 1.76
CIM (cm) 07.3±0.68c 15.2±0.62a 08.6±0.52b 2.10 1.18 1.77
AO (cm2) 0 4.3±0.43a 04.4±0.30a 00.9±0.12b 1.02 0.21 4.89
AA (cm2) 0 5.1±0.24a 05.5±0.43b 0 1.1±0.14c 1.08 0.22 5.00
AM (cm2) 0 1.9±0.27b 02.2±0.26a 00.5±0.08c 1.12 0.23 4.77
THO (cm) 00 6.3±0.17c 11.3±0.39a 0 6.8±0.40b 1.79 1.08 1.65
THA (cm) 0 6.5±0.16c 11.6±0.32a 0 6.8±0.41b 1.79 1.05 1.71
THM (cm) 3.6±0.36b 0 4.3±0.20a 0 4.1±0.22b 2.01 1.14 1.76
HO (cm) 02.8±0.19b 0 4.9±0.30a 0 2.9±0.21b 1.74 1.01 1.72
WO (cm) 01.3±0.10b 0 2.6±0.14a 0 1.1±0.07c 1.92 0.85 2.27
WA (cm) 01.1±0.05b 0 2.3±0.13a 0 0.9±0.06c 2.06 0.81 2.56
WM (cm) 0.8±0.05b 0 1.7±0.08a 0 0.7±0.09c 2.18 0.88 2.49
BTO 1 (cm) 00.6±0.11c 0 1.4±0.23a 0 0.8±0.09b 2.31 1.36 1.70
BTO 2 (cm) 0 0.2±0.05b 0 0.3±0.05a 0 0.1±0.05b 2.30 0.92 2.51
ABT (cm) 0.4±0.07c 0 0.9±0.12a 0 0.5±0.05b 2.31 1.28 1.81
BS 1 77.3±2.61b 86.6±2.46a 075.3±1.51b 1.12 0.98 1.15
BS 2 39.1±1.83a 40.5±1.32a 036.3±0.81b 1.04 0.93 1.11
BS 3 0 6.8±0.47b 08.1±0.52a 004.9±0.23c 1.20 0.72 1.67
SS 1-1 021.3±1.41b 22.9±1.21a 016.7±1.25c 1.08 0.79 1.37
SS 1-2 017.4±0.43b 20.1± 0.93a 013.4±0.45c 1.16 0.77 1.50
SS 2-1 211.1±15.74b 190.9±13.88c 251.4±3.49a 0.90 1.19 0.76
SS 3-1 028.2±4.72c 033.9±4.83b 42.4±5.03a 1.20 1.50 0.80
SS 3-2 045.4±8.43b 054.5±9.60b 0 72.9±10.13a 1.20 1.61 0.75
SS 3-3 011.1±2.45a 013.3±1.67a 12.0±3.93a 1.20 1.08 1.12
SS 4-1 068.8±5.80c 248.2±8.54b 276.7±20.01a 3.59 4.01 0.90

The values are means±SD (rock bream: n=10, olive flounder: n=30) of triplicated groups respectively. Means in rows with a same superscript letter are not significantly different (P > 0.05). Abbreviations (Figs. 2 and 3), SL: standard length; CIO: body circumference at one-third line between most posterior aspect of operculum and mediate point of standard length; CIA: body circumference at a vertical line which intersects at right angle with the intermediate point of standard length; CIM: body circumference at midpoint line between mediate point of standard length and most posterior scale in lateral line; AO: area on section at one-third line between most posterior aspect of operculum and mediate point of standard length; AA: area on section at a vertical line which intersects at right angle with the intermediate point of standard length; AM: area on section at midpoint line between mediate point of standard length and most posterior scale in lateral line; THO: total height on section at one-third line between most posterior aspect of operculum and mediate point of standard length; THA: total height on section at a vertical line which intersects right angle with the intermediate point of standard length; THM: total height on section at midpoint line between mediate point of standard length and most posterior scale in lateral line; HO: height on section at one-third line between most posterior aspect of operculum and mediate point of standard length; WO: width on section at one-third line between most posterior aspect of operculum and mediate point of standard length; WA: width on section at a vertical line which intersects at right angle with the intermediate point of standard length; WM: width on section at midpoint line between mediate point of standard length and most posterior scale in lateral line; BTO 1: belly thickness 1 on section at one-third line between most posterior aspect of operculum and mediate point of standard length; BTO 2: belly thickness 2 on section at one-third line between most posterior aspect of operculum and mediate point of standard length; ABT: average belly thickness, (BTO 1+BTO 2)/2; BS 1: body shape 1, (CIA/SL)×100; BS 2: body shape 2, (THA/SL)×100; BS 3: body shape 3, (WA/SL)×100; SS 1-1: section shape 1-1, (WO/THO)×100; SS 1-2: section shape 1-2, (WA/THA)×100; SS 2-1: section shape 2-1, (HO/WO)×100; SS 3-1: section shape 3-1, (ABT/WO)×100; SS 3-2: section shape 3-2, (BTO 1/WO)×100; SS 3-3: section shape 3-3, (BTO 2/WO)×100; SS 4-1: section shape 4-1, [0.5(π×HO×0.5×WO)/AO]×100; Ratio 1: fed group/initial group; Ratio 2: starved group/initial group; Ratio 3: fed group/starved group.

Download Excel Table

In olive flounder the SL was significantly greater (P < 0.05) in the fed group compared with the control group (1.72-fold) and the starved group (1.53-fold). The values for body circumference, section area, section height, and section width were significantly higher (P < 0.05) in the fed group than in the initial and starved groups. Relative to the initial group, the body circumference value in the starved group was higher but the section area and width values were lower (P < 0.05). The values for BTO 1, BTO 2 and ABT related to abdominal cavity thickness were higher in the fed group than in the starved group (P < 0.05). The SS 1-1, SS 1-2, and SS 2-1 morphometric dimensions are related to body width and body height. The value of SS 2-1 was significantly higher in the starved group relative to the fed and initial groups (P < 0.05), while the values of SS 3-1, SS 3-2, and SS 4-1 were higher in the starved group relative to the fed group (P < 0.05).

Rations 1(fed group/ initial group) of all dimensions on rock bream were lower than those on olive flounder. That is, growth of olive flounder was faster than rock bream. Ration 2 (starved group/initial group) of all dimensions on rock bream were below 1.0, respectively. Ration 2 of AO, AA and AM on rock bream were higher than those on olive flounder. Rations 2 of SL, CIO, CIA, CIM, THO, THA and THM on rock bream were lower than those on olive flounder. In addition, rations 2 of the other dimensions on rock bream were lower than those on olive flounder. Rations 3 (fed group/ staved group) of all dimensions on olive flounder were higher than rock bream. In other words, difference of morphometric characteristic between fed a1nd starved group on olive flounder was higher than rock bream. Therefore, effects of starvation on rock bream were more noticeable than those on olive flounder.

DISCUSSION

At completion of the eight-week experimental period specimens of rock bream, Oplegnathus fasciatus, the SL and BW had increased in the fed group, but these parameters had decreased in fish in the starved group (P < 0.05). In particular, the loss of BW in the starved group was more precipitous (P < 0.05). In olive flounder, Paralichthys olivaceus, the SL and BW also increased in the fed group (P < 0.05), but decreased in the starved fish (Park et al., 2006). Thus, in both species decreased growth was evident in the starvation group, which is similar to the results obtained by Sumpter et al. (1991) during four-week starvation experiment involving rainbow trout, Oncorhynchus mykiss. During a 12-week starvation experiment involving olive flounder, Park et al. (2006) reported growth inhibition in starved fish was evident in the condition factor, specific growth rate, growth rate as a function of BW, and GW. An increase in the DP of starved fish has been attributed to a decrease in the VW. Park et al. (2006) reported that in olive flounder the DP in starved fish increased but the VW decreased. They found that the fed group had significantly greater weight, GW, and VW compared with the starved group, but the two groups were not significantly different with respect to the VI. This was because of the relatively high VI according to energy consumption for accumulating primary muscles by starving in the starved group, and this energy consumption caused a decrease in weight in the starved group (Park et al., 2006).

In the starved group the truss dimensions 1×2, 1×9, 1×10, 4×5, 4×6, and 5×6, and the classical dimensions 1×2, 1×3, 1×5, 1×10, and 1×12 increased in rock bream (P < 0.05). These results are indicative of the decrease in SL in the starved group. The head connection morphometric analysis showed increases in both truss and classical dimensions in the starved group, but the classical dimensions decreased in the fed group (P < 0.05). Classical and truss dimensions in the head region have also been reported to increase significantly in Chinese minnow, Rhynchocypris oxycephalus during nine weeks of starvation (Park et al., 2001). According to Park et al. (2007) there were significant decreases in classical head dimensions in a fed group of olive flounder, while in a starved group there were significant decreases in classical dimensions in relation to the anterior-posterior body axis. This is inconsistent with the observation of Currens et al. (1989), who reported that while the truss dimensions of the head were generally large in rainbow trout and chinook salmon, O. tshawytscha under various feeding regimes, the trunk dimensions were smaller (Park et al., 2007). In rock bream the trunk region dimensions, including a large component of body depth, are likely to be variable because of differences in the feeding regimes of fish in differing habitats. In olive flounder the truss dimensions for almost the entire trunk region increased significantly in the fed group, while in the starved group the dimensions of the trunk region in relation to body depth decreased significantly (Park et al., 2007). In the Chinese minnow study noted above (Park et al., 2001), both the truss and the classical head and trunk region dimensions were generally affected in fed or starved fish, and it was hypothesized that physiological changes in fat metabolism could explain the differences observed between the fed and starved fish. These results are similar to those reported by Theilacker (1978), who noted that body shape dimensions, especially body depth, reflected nutritional conditions (Park et al., 2001). In another study, Currens et al. (1989) suggested that the trunk region was the site of greatest fat deposition and loss during periods of feeding and fasting in salmonid fish.

Dimensions that did not significantly differ among all three feeding regimes were the truss dimensions 1×8, 2×3, 2×7, 2×8, 2×9, 3×5, 3×6, 3×7, and 6×7, and the classical dimensions 1×7, 1×8, 1×11 and 6×7 (P > 0.05). These results indicate that these body parts are less likely to be affected by food availability or quality. Similar results were reported for morphometric characteristics in olive flounder (Park et al., 2007). Thus, these truss and classical dimensions may be useful taxonomic features for discriminating species of rock bream and olive flounder. Previous studies have used caudal region dimensions in salmonid fry, and other truss and classical dimensions in Chinese minnow, as taxonomic indicators (Currens et al., 1989; Park et al., 2001).

In rock bream and olive flounder the fed group generally exhibited higher values for body circumference parameters, including cross-cut sectional area and total height, compared with these dimensions in the starved group (P < 0.05). Most of these parameters were also smaller in the starved group than in the initial group (P < 0.05). Body height and truss dimensions have previously been determined in feeding and starvation experiments (Park et al., 2007). Significant changes were observed in the ‘A’ and ‘M’ line regions in terms of total height and area in relation to body circumference, relative to the ‘O’ line region. The trunk is the most likely region to show changes resulting from feeding or starvation. Park et al. (2002) attribute the thinness of the abdominal cavity in starved fish to fasting-induced endogenous absorption of energy from this region. As thicker fish are more profitable from a commercial standpoint (Gjerde & Schaeffer, 1989), starved fish will inevitably be of lower value. Park et al. (2002) suggested that during starvation phenotypic variation occurs firstly in dorsal fins of the abdominal region and secondly in pectoral fins. This is similar to the report of Lee et al. (1998), who noted that the primary impact of starvation in Chinese minnow was evident in the abdominal area. Park et al. (2001) also noted that the upper body truss dimension and the body depth classical dimension decreased significantly in starved Chinese minnow. The morphometric dimensions SS 1-1, SS 1-2, and SS 2-1 in two species are related to body width and body height. The results of this experiment showed that the cross-cut section of the fed group was more circular than that of the starved group. This characteristic is an indication of high commercial value (Gjerde & Schaeffer, 1989).

The study has conducted on effect of starvation until now. Hur et al. (2006a) reported the effects of nutritional conditions on changes in condition factor, liver somatic index, and hepatocyte ultrastructure in the olive flounder. Hur et al. (2006b) also investigated the influence of nutritional conditions on histological changes in melano-macrophage accumulation in the kidney, caused by long-term starvation. During starvation, essential processes in fish are maintained at the expense of accumulated energy reserves, resulting in the progressive depletion and wastage of body tissues. Therefore, studies of fish nutrition in relation to growth and condition can increase understanding of the responses of wild and cultured fish to feed conditions (Weatherley & Gill, 1987; Lee et al., 1998; Park et al., 1998; Park et al., 2001). Analysis of the various dimensions investigated in this study has been shown to provide an accurate indication of the nutritional condition of other fish.

ACKNOWLEDGEMENTS

This research was funded through Project 2010-0021293 of the National Research Foundation of Korea, Korea. We are grateful to the staff of the Fishery Genetics and Breeding Science Laboratory of the Korea Maritime and Ocean University, Korea. This manuscript was improved by comments from anonymous reviewers. All of the experiments performed in this study complied with the current laws of Korea (the Law Regarding Experimental Animals, No. 9932) and the Ethical Guidelines of Korea Maritime and Ocean University, Korea.

REFERENCES

1.

Choi Y, Kim JH, Park JY. Sea Fish in Korea. 2002KyoHak Publish. CoSeoul. Korea-384.

2.

Currens KP, Sharpe CS, Hjort R, Schreck CB, Li WH. Effect of different feeding regimes on the morphometrics of chinook salmon (Oncorhynchus tshawtscha) and rainbow trout (O. mykiss). Copeia. 1989; 3 p. 689-695.

3.

Duncan DB. Multiple-range and multiple F tests. Biometrics. 1955; 1 p. 1-42.

4.

Gjerde B. Body traits in rainbow trout: Phenotypic means and standard deviation and sex effects. Aquaculture. 1989; 80 p. 7-24.

5.

Gjerde B, Schaeffer LR. Body traits in rainbow trout: Phenotypic means and standard deviation and sex effects. Aquaculture. 1989; 80 p. 25-44.

6.

Hubbs CL, Lagler KF. Fishes of the Great Lakes region. Cranbrook Inst Sci Bull. 1947; 26 p. 1-186.

7.

Humphries JM, Bookstein FL, Chernoff B, Smith GR, Elder RL, Poss SC. Multivariate discrimination by shape in relation to size. Syst Zool. 1981; 30 p. 291-308.

8.

Hur JW, Jo JH, Park IS. Effects of long-term starvation on hepatocyte ultrastructure of olive flounder, Paralichthys olivaceus. Ichthyol Res. 2006a; 53 p. 306-310.

9.

Hur JW, Woo SR, Jo JH, Park IS. Effects of starvation on kidney melano-macrophage centre in olive flounder, Paralichthys olivaceus (Temminck and Schlegel). Aquacult Res. 2006b; 37 p. 821-825.

10.

Ihssen PE, Booke HE, Casslman JM, McGlade JM, Payne NR, Utter FM. Stock identification: materials and methods. Can J Fish Aquat Sci. 1981; 38 p. 1838-1855.

11.

Lee CK, Park IS, Hur SB. Influence of starvation on the variations of hepatocyte nucleus in larvae of red spotted grouper, Epinephelus akaara. J Aquacult. 1998; 11 p. 11-17.

12.

Lee KK, Kim YH, Park IS. Effect of starvation on some nutritional parameters in Rhynchocypris oxycephalus. 1. Characteristics of the histological and biochemical changes. Korean J Ichthyol. 1999; 11 p. 33-41.

13.

Mustafa S, Mittal A. Protein, RNA and DNA levels in liver and brain of starved, catfish. J Ichthyol. 1982; 28 p. 396-400.

14.

Park IS. Histological changes of hepatocyte and intestinal epithelium during starvation in olive flounder, Paralichthys olivaceus. J Korean Fish Soc. 2006; 39 p. 303-307.

15.

Park IS, Hur JW, Choi JW. Hematological responses, survival, and respiratory exchange in the olive flounder, Paralichthys olivaceus, during starvation. Asian-Aust J Effects of Starvation in Rock Bream and Olive Flounder Anim Sci. 2012; 25 p. 1276-1284.

16.

Park IS, Im JH, Jeong CH, Noh JK, Kim YH, Lee YH. Effect of starvation on some nutritional parameters in Rhynchocypris oxycephalus (Sauvage and Dabry). 2. Characteristics of the morphometric changes in the sectioned body. Korean J Ichthyol. 2002; 14 p. 11-18.

17.

Park IS, Im JM, Ryu DK, Nam YK, Kim DS. Effect of starvation on morphometric changes in Rhynchocypris oxycephalus (Sauvage and Dabry). J Appl Ichthyol. 2001; 17 p. 277-281.

18.

Park IS, Lee CK, Im JH, Kim JH, Kim SU. Effect of starvation on the growth and hepatocyte nuclear size of larval rockfish Sebastes schlegeli and larval spotted sea bass Lateolabrax sp. J Aquacult. 1998; 11 p. 345-352.

19.

Park IS, Woo SR, Kim EM, Cho SH. Effect of feeding and starvation on growth and phenotypic traits in olive flounder, Paralichthys olivaceus (Temminck et Schlegel). J Aquacult. 2006; 19 p. 183-187.

20.

Park IS, Woo SR, Song YC, Cho SH. Effects of starvation on the morphometric characteristics of olive flounder Paralichthys olivaceus. Ichthyol Res. 2007; 54 p. 297-302.

21.

Riddell BE, Leggett WC, Saunders RL. Evidence of adaptive polygenic variation between two populations of Atlantic salmon (Salmo salar) native to tributaries of the S. W. Miramichi River. N. B. Can J Fish Aquat Sci. 1981; 38 p. 321-333.

22.

Seol DW, Hur JW, Kim DS, Nam YK, Bang IC, Park IS. Effect of starvation on kidney melano-macrophage centre in sub-adult rock bream, Oplegnathus fasciatus. J Fish Sci Technol. 2009; 12 p. 49-53.

23.

Straüss RE, Bookstein FL. The Truss: body from reconstructions in morphometrics. Syst Zool. 1982; 31 p. 113-135.

24.

Sumpter JP, Le Bail PY, Pickering AD, Pottinger TG, Carragher JF. The effect of starvation on growth and plasma growth hormone concentrations of rainbow trout, Oncorhynchus mykiss. Gen Comp Endocr. 1991; 83 p. 94-102.

25.

Sun ZZ, Liu XZ, Xu YJ, Li J, Qu JZ, Lan GG, Liang F. Effects of starvation on the growth and development of larval and juvenile rock bream, Oplegnathus fasciatus. Mar Fish Res. 2009; 30 p. 8-13.

26.

Taylor EB, McPhail JD. Variation in burst and prolonged swimming performance among British Columbia populations of coho salmon (Oncorhynchus kisutch). Can J Fish Aquat Sci. 1985; 42 p. 2029-2033.

27.

Theilacker GH. Effect of starvation on the histological and morphological characteristics of jack mackerel, Trachurus symmetricus, larvae. Fish Bull. 1978; 76 p. 403-414.

28.

Weatherley AH, Gill HS. The Biology of Fish Growth. 4. Protein. Lipid and Caloric Contents. 1987; Academic PressLondon p. 139-146.

29.

Winans GA. Multivariate morphometric variability in Pacific salmon: Technical demonstration. Can J Fish Aquat Sci. 1984; 41 p. 1150-1159.