Some biological aspects of mackerel scad (Decapterus macarellus) in Ambon Island waters, Indonesia

Abstract

Abstract
Mackerel scads (Decapterus spp) are important small pelagic fishes in Ambon Island waters and dominate the catch of purse seine in term of number and volume. One of the species of mackerel scads that can be found all year round in the area is Decapterus macarellus, however, there is no biological information about this species from Ambon Island waters. This research was conducted to study some biological aspects which consist of size distribution, growth pattern and condition factor of mackerel scad (D. macarellus) in Ambon Island waters. Samples of mackerel scad were collected weekly from purse seine fishers at Hitu village, Ambon Island, Maluku Province on February to March 2018. Totally, there were 279 of mackerel scad collected during the study with the total length ranging from 11.0 to 24.5 cm (mean 17.22±2.48cm) while the weight between 13 and 136g (mean 50.4±23.8g). Analysis of length-weight relationship showed that mackerel scad in the area have isometric and positive allometric growth pattern with condition factor close to unity.

Full text

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International Journal of Fisheries and Aquatic Studies 2018; 6(4): 171-175
E-ISSN: 2347-5129
P-ISSN: 2394-0506
(ICV-Poland) Impact Value: 5.62
(GIF) Impact Factor: 0.549
IJFAS 2018; 6(4): 171-175
© 2018 IJFAS
www.fisheriesjournal.com
Received: 12-05-2018
Accepted: 14-06-2018
Jesaja A Pattikawa
(a) Department of Aquatic Resource
Management, Faculty of Fishery and
Marine Science, Pattimura University
Ambon, Indonesia
(b) Maritime and Marine Science
Center of Excellence, Pattimura
University, Ambon, Indonesia
OTS Ongkers
(a) Department of Aquatic Resource
Management, Faculty of Fishery and
Marine Science, Pattimura University
Ambon, Indonesia
(b) Maritime and Marine Science
Center of Excellence, Pattimura
University, Ambon, Indonesia
JMS Tetelepta
(a) Department of Aquatic Resource
Management, Faculty of Fishery and
Marine Science, Pattimura University
Ambon, Indonesia
(b) Maritime and Marine Science
Center of Excellence, Pattimura
University, Ambon, Indonesia
PrA Uneputty
(a) Department of Aquatic Resource
Management, Faculty of Fishery and
Marine Science, Pattimura University
Ambon, Indonesia
(b) Maritime and Marine Science
Center of Excellence, Pattimura
University, Ambon, Indonesia
A Amirudin
Department of Aquatic Resource
Management, Faculty of Fishery and
Marine Science, Pattimura University
Ambon, Indonesia
Correspondence
Jesaja A Pattikawa
(a) Department of Aquatic Resource
Management, Faculty of Fishery and
Marine Science, Pattimura University
Ambon, Indonesia
(b) Maritime and Marine Science
Center of Excellence, Pattimura
University, Ambon, Indonesia
Some biological aspects of mackerel scad (Decapterus
macarellus) in Ambon Island waters, Indonesia
Jesaja A Pattikawa, OTS Ongkers, JMS Tetelepta, PrA Uneputty and A
Amirudin
Abstract
Mackerel scads (Decapterus spp) are important small pelagic fishes in Ambon Island waters and
dominate the catch of purse seine in term of number and volume. One of the species of mackerel scads
that can be found all year round in the area is Decapterus macarellus, however, there is no biological
information about this species from Ambon Island waters. This research was conducted to study some
biological aspects which consist of size distribution, growth pattern and condition factor of mackerel scad
(D. macarellus) in Ambon Island waters. Samples of mackerel scad were collected weekly from purse
seine fishers at Hitu village, Ambon Island, Maluku Province on February to March 2018. Totally, there
were 279 of mackerel scad collected during the study with the total length ranging from 11.0 to 24.5 cm
(mean 17.22±2.48cm) while the weight between 13 and 136g (mean 50.4±23.8g). Analysis of length-
weight relationship showed that mackerel scad in the area have isometric and positive allometric growth
pattern with condition factor close to unity.
Keywords: Decapterus macarellus, size distribution, growth pattern, condition factor, Ambon
1. Introduction
Maluku is an archipelago province in Indonesia with about 92% of its territorial area is
covered by sea water. One of the islands that belong to Maluku Province is Ambon Island.
Even though the island is small but its seawater has great potential of marine resources
especially reef fishes and small pelagic fishes [1, 2, 3, 4, 5].
Small pelagic fishes that dominate the catch and occur all year round in Ambon Island waters
are mackerel scads (Decaterus spp) [3, 5]. There are four species of mackerel scads in
Indonesian waters including Ambon Island waters namely Decapterus kuroides, D.
macarellus, D. russelli, and D. macrosoma [6]. These species are mainly caught by using purse
seine or locally known as jaring bobo [5].
Even though mackerel scads can be caught all year round, there is concern about their
sustainability. There is an increasing of the number of purse seine in the area but it is not
followed by significant increasing in total catch. In 2014, the number of purse seine almost
doubled compared to the number in 2010 but their total catch only increased about 13% [7]. In
addition, biological information on mackerel scads in Ambon Island waters is still lacking.
There were some studies on mackerel scads in the area but its only covered the species of D.
macrosoma and D. russelli [3, 5, 8, 9]. Therefore, this research was conducted study some
biological aspects namely size distribution, growth pattern and condition factor of mackerel
scad (D. macarellus) in Ambon Island waters.
2. Materials and Methods
2.1 Study area
This research was conducted at Hitu village (Figure 1), Northern Ambon Island, Maluku
Province, Eastern Indonesia on February to March 2018.

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International Journal of Fisheries and Aquatic Studies
N
Fig 1: Sampling site (red square)
2.2 Data collection and analysis
Samples of mackerel scad were collected weekly from purse
seine fishers and then brought to the laboratory to measure.
Total length of fish was measured from tip of the mouth to tip
of the tail by using plastic ruler to the nearest mm, whereas
weight was weighted using a 5.0 kg blue LCD black light
portable digital balance to the nearest gram. Data was
processed with Microsoft Excel 2010
Length weight relationship was analysed by using power
function [10]:
W = a L b
Where: W = weight (g);
L = Total length (cm);
a = intercept;
b = slope.
Interval value of slope (b) at p=0.05 was calculated according
to King (2007) [11]:
b ± t x sb
Where: t = t table (p=0.05; df=n-2);
sb = standard deviation of b
Relative condition factor was estimated using formula
proposed by King (2007) [11]:
CF = Ŵ/W
Where: Ŵ = observed weight
W = predicted weight = aLb
3. Results and discussion
3.1 Size distribution
Totally, there were 279 individuals of mackerel scad (D.
macrosoma) collected during six weeks period of study. Total
length of mackerel scad ranged from 11.0 – 24.5 cm (mean
17.22 ± 2.48 cm) while the weight ranged from 13 – 136 g
(mean 50.4 ± 23.6 g)(Table 1). It can be seen in Table 1 that
there are the same trend in size distribution i.e. minimum
length and weight occurred in periods I and VI, maximum
sizes only found in period VI while the highest mean of
length and weight found in period III.
The fish size found in this study was smaller than the size of
mackerel scad reported in other areas in Indonesian waters. In
North Maluku waters, total length of mackerel scad ranged
from 21.1 – 31.5 cm with the weight ranged between 101.8
and 307.5 g [12], while in Kendari waters (Southeast Sulawesi)
total length ranged from 18.2 – 31.7 cm with the weight
ranged from 58 – 291 g [13]. It was also reported from Kendari
waters that fork length of mackerel scad caught in the area
ranged from 14 – 32 cm [14], whereas in Majene waters (West
Sulawesi) fork length of mackerel scad ranged from 14 - 22
cm with the weight ranged from 70.1 – 187.6 g [15]. In
addition, fork length of mackerel scad ranged from 16 – 32
cm in Banda Aceh waters (Western Indonesia) [16].
Table 1: Size distribution of Decapterus macarellus during the study period
Period
n (ind.)
Total length total (cm)
Weight (g)
Min
Max
SD
Min
Max
SD
I
51
11.0
21.0
17.08
2.22
13
98
46.3
19.6
II
45
12.0
24.0
17.22
3.07
19
132
52.8
32.3
III
39
14.0
22.5
17.15
2.08
24
107
51.3
22.5
IV
43
14.0
22.5
18.02
2.00
18
110
57.9
20.8
V
46
13.0
22.0
17.18
2.32
18
103
51.7
21.6
VI
55
11.0
24.5
16.82
2.84
13
136
47.0
25.5
Total
279
11.0
24.5
17.22
2.48
13
136
50.4
23.6
Notes: Min=minimum; max=maximum; = mean; SD=standard deviation
Length frequency distribution of mackerel scad in Ambon
Island waters for the whole periods is presented in Figure 2. It
can be seen in Figure 2 that mid-length 17.5 cm had the
highest number of individual i.e. 24.43% of the total fish
collected while the lowest belonged to mid-length 23.5 cm
with only 1 individual (0.36%). The modal found in this study
is different compare to mackerel scad in Banda Aceh waters
i.e. at mid-fork length of 28.5 cm [16].

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International Journal of Fisheries and Aquatic Studies
Fig 2: Length frequency distribution of Decapterus macarellus
Maturity of mackerel scad in Indonesian waters varies. In
Banda Aceh waters, maturity of mackerel scad occurred at
24.9 cm in fork length [16] while in North Maluku at total
length of 25.8 cm [16]. Based on those information and the
maximum length of mackerel scad in Ambon Island waters
(24.5 cm) (see Table 1 and Figure 3), it seems that fish caught
by purse seine in this area consist of immature individuals. If
this trend of exploitation still continues and occurs for long
time, sustainability of mackerel scad population in Ambon
Island waters is in danger. Effendie (1997) [17] stated that to
ensure sustainability of marine resource, fish should be caught
after it spawned at least once. According to Pauly (1984) [10],
growth overfishing in an area occurs if the catch mostly
consist of young fishes or immature ones.
Fig 3: Cumulative relative frequency of Decapterus macarellus
3.2 Growth pattern
Length weight relationship of mackerel scad in Ambon Island
waters are presented in Table 2 and Figure 4. The values of
coefficient of correlation (r) shown in Table 2 ranged from
0.937 – 0.976 are larger than r table (critical value of r at
p=0.01; df=n-2). These figures indicate that there are highly
significant relationships between length and weight and those
relationships can be used for further analysis. Contribution of
length to weight as shown by determination coefficients (R2)
in Table 2 and Figure 4 ranged from 87.4 – 95.3%.
The values of slope (b) shown in Table 2 and Figure 4 ranged
from 2.912 – 3.371. Table 2 also showed interval value of b at
p=0.05 to test significance deviation of b from 3. According
to King (2007) [11], b is not significantly different from 3
(b=3) if its interval value at p=0.05 includes 3.00.
Furthermore, Sparre and Venema (1992) [18] stated that the
value of b in length weight relationship can be used to
determined growth pattern of fish. In addition Pauly (1984)
[10] stated that if b = 3, growth pattern of fish is isometric i.e.
length increment is proportional to weight while if b ≠ 3
means length increment is larger than weight increment
(negative allometric, b<3) or weight increment is larger than
length increment (positive allometric, b>3). Based on those
statements and the interval values of b at p=0.05 listed in
Table 2, it seems that isometric growth pattern i.e. length
increment has the same rate with weight increment occurred
in periods I, II, V and VI while positive allometric growth
pattern i.e. weight increment is faster than length increment
found in periods III and IV.
Table 2: Length weight relationship and growth pattern of Decapterus macarellus
Period
W = a L b
r
R2
Interval of b p = 0.05
Growth pattern
I
W = 0.005 L 3.185
0.968
0.937
2.948 – 3.421
Isometric
II
W = 0.011 L 2.944
0.966
0.932
2.700 – 3.188
Isometric
III
W = 0.005 L 3.249
0.976
0.953
3.009 – 3.489
Positive Allometric
IV
W = 0.003 L 3.371
0.948
0.898
3.013 – 3.730
Positive Allometric
V
W = 0.007 L 3.129
0.973
0.947
2.903 – 3.355
Isometric
VI
W = 0.012 L 2.912
0.935
0.874
2.607 – 3.217
Isometric
Total
W = 0.007 L 3.092
0.954
0.911
2.978 – 3.206
Isometric

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International Journal of Fisheries and Aquatic Studies
Fig 4: Length weight relationship of Decapterus macarellus during the study period
Study on length weight relationship mackerel scad in
Indonesian waters is limited. Mackerel scad in Majene, West
Sulawesi showed positive allometric growth pattern in July
and negative allometric in April to June [15]. Negative
allometric growth pattern also reported for male and female
mackerel scad in North Maluku waters [12]. According to
LeCren (1951) [19] and Froese (1998, 2006) [20, 21], variation in
growth pattern of fish possibly due to sex, maturity, location,
season and food availability.
Effendie (1997) [17] stated that length weight relationship is
very useful in fisheries research when there is requirement for
statistical conversion from length to weight or vice versa.
Therefore, the result of this research should be useful for
biomass evaluation of mackerel scad in Ambon Island waters.
3.3 Condition Factor
Length weight relationship can be used also to determine
condition factor or well-being and fitness of fish in term of
ability to survive and reproduce [15]. Condition factor used in
this study is relative condition factor i.e. ratio between
observed weight and predicted weight based on length weight
relationship. The value of condition factor during the research
is presented in Table 3.

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International Journal of Fisheries and Aquatic Studies
Table 3: Relative condition factor of Decapterus macarellus
Period
Condition factor
Interval
Mean
SD
I
0.86 – 1.25
1.03
0.10
II
0.77 – 1.63
1.01
0.16
III
0.73 – 1.07
0.93
0.08
IV
0.65 – 1.48
1.05
0.13
V
0.83 – 1.25
0.98
0.10
VI
0.51 – 1.62
0.97
0.18
Total
0.54 – 1.78
1.01
0.14
It can be seen it Table 3 that the values of condition factor of
mackerel scad in Ambon Island waters varies ranged from
0.54 – 1.78, however their average are close to unity during
the period of study. According to Effendie (1997) [17], an ideal
condition of fish can be achieved if the value of relative
condition factor is unity or close to unity in which length
increment is proportional to weight increment or isometric
growth pattern (b = 3). Furthermore, Le Cren (1951) [19] stated
that condition factor of fish is affected by environment,
season, maturity and food. As condition factor found this
study is close to unity, it indicated that mackerel scad in
Ambon Island waters can grow well and reproduce.
4. Conclusion and recommendation
Result of this study shows that mackerel scad caught by purse
seine in Ambon Island are small in size and immature.
Growth pattern of this species in the area show isometric and
positive allometric with condition factor close to unity.
Information of mackerel scad in Maluku waters is limited;
therefore more research should be conducted to study other
biological aspects such as reproduction and population
dynamics of this species.
5. References
1. Limmon GV, Rijoly F, Ongkers OTS, Loupatty SR,
Pattikawa JA. Reef fish in the southern coastal waters of
Ambon Island, Maluku Province, Indonesia. AACL
Bioflux, 2017; 10(2):234-240.
2. Limmon GV, Khouw AS, Loupatty SV, Rijoly F,
Pattikawa JA. Species richness of reef food fishes in
Ambon Island waters, Maluku Province, Indonesia.
AACL Bioflux. 2017; 10(3):507-511.
3. Ongkers OTS, Pattikawa JA, Rijoly F. Biological aspects
of scad mackerel (Decapterus russelli) in Latuhalat
waters, Nusaniwe District, Ambon Island. Omni-
Akuatika. 2016; 12(3):79-87. (in Indonesian)
4. Rijoly F, Natan Y, Pattikawa JA, Ongkers OTS,
Uneputty PrA. Community structure of fish in inner
Ambon bay, Maluku, Indonesia. International Journal of
Fisheries and Aquatic Studies. 2016; 4(5):264-269.
5. Pattikawa JA, Tetelepta JMS, Ongkers OTS, Uneputty
PrA, Lewerissa H. Size distribution, length-weight
relationship and age group of Decapterus macrosoma in
eastern waters of Ambon Island, Indonesia. AACL
Bioflux. 2017; 10(4):969-976.
6. Atmaja SB, Sadhotomo B. Study on the reproduction of
"layang deles" shortfin scad (Decapterus macrosoma) in
the Java Sea. Indonesian Fisheries Research Journal.
2005; 11:9-19.
7. BPS Maluku. Maluku in Figures. BPS Provinsi Maluku,
2015, 624
8. Syahailatua A, Sumadhiharga OK. Population dynamic
of scads (Decapterus russelli and D. macrosoma) in
Ambon Bay. Torani, 1991; 1(6):31-46. [In Indonesian].
9. Syahailatua A. Biological aspects and exploitation of
scad Decapterus russelli andD. macrosoma in Ambon
Bay. Paper presented at Riptek Seminar BPPT. 2004 [In
Indonesian].
10. Pauly D. Fish Population Dynamics in Tropical Waters:
A Manual for Use with Programmable Calculators.
ICLARM, Manila, 1984, 325.
11. King M. Fisheries biology, assessment and
management.Wiley-Blackwell, UK, 2007, 400.
12. Iksan KH, Irham. Growth and reproduction of mackerel
scads, Decapterus macarellus (Cuvier, 1833) in North
Moluccas waters. Jurnal Iktiologi Indonesia. 2009;
9(2):163-174. (in Indonesian).
13. Fadila M, Asriyana, Tadjuddah M. Some aspects of
reproduction biology of Malalugis fish (Decapterus
macarellus) from purse seine catches landed at Kendari
Fish Port Landing Jurnal Manajemen Sumber Daya
Perairan. 2016; 1(4):343-353. (in Indonesian).
14. Hariati T. The exploitation rate of both short fin scad
(Decapterus macrosoma) and mackerel scad (Decapterus
macarellus) from Kendari waters. J Lit. Perikan. Ind.
2011; 17(1):31-40. (in Indonesian).
15. Nur M, Ihsan MN, Tenriware, Atjo AA. Length - Weight
Relationship of Scad Mackerel (Decapterus macarellus
Cuvier, 1833) in Majene Waters, West Sulawesi Jurnal
SAINTEK Peternakan dan Perikanan. 2017; 1(1):40-44.
(in Indonesian).
16. Hariati T. Mackerel scad (Decapterus macarellus), one of
the small pelagic species in Indonesia. Warta Penelitian
Perikanan Indonesia. Edisi Sumber daya dan
Penangkapan. 2004; 11(5):15-18. (in Indonesian).
17. Effendie MI. Fishery Biology. Yayasan Pustaka
Nusatama, Yogyakarta, 1997, 163. (in Indonesian).
18. Sparre P, Venema SC. Introduction to Tropical Fish
StockAssement Part-1. Manual. FAO Fish Tech Pap
306/1, Rome, 1992, 376.
19. LeCren ED. The length-weight relationship and
seasonalcycle in gonad weight and condition in the perch
(Percafluviatilis). J Anim. Ecol. 1951; 20:201-219.
20. Froese R. Length-weight relationship for 18 less-studied
fish species. Journal of Applied Ichthyology. 1998;
14:117-118.
21. Froese R. Cube law. Condition factor and weight –
Length relationships: history, meta- analysis and
recommendations. Journal of Applied Ichthyology. 2006;
22:241-253.