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American Journal of  
Life Science and Innovation (AJLSI)

Comparative Morphological Analysis of  Pellonula Leonensis Fished from Isaba 
Creek and New Calabar River, Niger Delta Region, Nigeria

Nwafili S.A1*, Eloho Sorhor1

Volume 2 Issue 2, Year 2023
ISSN: 2833-1397 (Online)

DOI: https://doi.org/10.54536/ajlsi.v2i2.1549
https://journals.e-palli.com/home/index.php/ajlsi

Article Information ABSTRACT

Received: April 12, 2023

Accepted: June 09, 2023

Published: June 16, 2023

The samall-toothed pellonula, Pellonula leonensis is ecologically and economically important. 
It is good source of  protein to rural coastal and riverine communities because of  its taste. 
Despite the economic significance, information on its biology are scarce. We evaluated 
the morphometric and meristic traits of  the species from two water bodies in the Niger 
Delta Region. The population obtained from ISABA Creek, Delta State were significantly 
(P˂0.05) smaller in all the morphometric traits analysed relative to the population from 
New Calabar River with the exception of  Pectoral Fin Length (PFL) and Pelvic Fin 
Length (PvFL). The range of  total length, TL and weight respectively of  3.70-8.52cm 
(X ̅=5.14±0.034cm) and 0.20-3.40g (X ̅=0.75±0.022g) for ISABA Creek population and 
6.5-9.80cm (X ̅=8.35±0.06cm) and 1.7-7.30 g (X ̅=3.84±0.083g) for New Calabar River 
population was observed. The range of  meristic characters significantly differed between 
the two waters bodies (p<0.05). The observed intraspecies differences could be attributed 
to environmental variables, fishing pressure and genetic factors. This study reveals the need 
for developing conservation strategies and domestication programs for species distributed 
in different water system. 

Keywords

Pellonula Leonensis, Isaba 
Creek, New Calabar River, 
Morphological Traits, 
Geographic Isolation, 
Intraspecies Differences

INTRODUCTION
The fresh and brackish waters of  tropical Africa boast 
of  about 20 species of  clupeids and one of  them is 
Pellonula leonensis with wide spread distribution in both 
remote Sahelian and coastal basins (Reid and Sydenham, 
1979, Teugels, et al., 1992; Gourene & Teugels, 2003). 
Pellonula is essentially a riverine fish that can inhabit both 
fast-flowing and calm, muddy habitats, lakes and creeks 
(Lowe-McConnell, 1987), near the shore (Turner, 1994). 
Information on the biology of  Pellonula leonensis are scarce 
in the rivers and coastal areas of  the Niger Delta Region. 
However, Ikomi (1995) and Kingdom and Allison, 
(2007a; b) have reported on aspects of  the species’ 
biology in the Warri and Nun Rivers, respectively. The 
Small-toothed Pellonula is of  commercial importance in 

communities around New Calabar River (NCR), Rivers 
State and Isaba Creek (ISC), Delta State, fetching good 
income on basis of  account of  its tasty characteristics.  
This study evaluates and compares the morphometric 
and meristic characteristics of  P. leonensis from the two 
water bodies (NCR and ISC) in the Niger Delta Region.  
There is no record of  any research on the species from 
the two water bodies.

MATERIALS AND METHODS
Samples Collection
The samples of  pellonula species were procured from 
fishermen operating in Isaba Creek, Delta State and New 
Calabar River, Rivers State in the Niger Delta Region 
(Table 1).

1 Department of  Fisheries, Faculty of  Agriculture, University of  Port Harcourt PMB, 5323, Nigeria
* Corresponding author’s e-mail: sylvanus.nwafili@uniport.edu.ng

 Table 1: Sampling Location and Size
Sampling location Latitude Longitude N
Isaba Creek 5.42749° or 5° 25' 39" north 5.69516° or 5° 41' 43" east 614
New Calabar River 4.41939° or 4° 25' 10" north 7.02001° or 7° 1' 12" east 168
Total 782

The species was identified according to Gourène and 
Teugels (1991, 2003) and specimens collected were 
stored in ethanol (97% alcohol). The morphometric 
characteristics were measured on each individual with a 
metre rule (Cm) and the body weight (g) was measured 
with a Mini-digital weighing scale for the following 
parameters: Anal Fin Length (AFL), Body Depth (BD), 

Caudal Fin Length (CFL), Caudal Peduncle (CP), Distance 
between the pectoral and anal fin (DBPAF), Dorsal Fin 
Length (DFL), Eye diameter (ED), Head Depth (HD), 
Head length (HL), Pectoral Fin Length (PFL), Pelvic 
Fin Length (PvFL), Pre-Dorsal Length (PrDL), Pre-
Pectoral Length (PrPFL), Pre-Pelvic Length (PrPvFL), 
Pre-Orbital Length (PrOL), Standard Length (SL), Fork 



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Am. J. Life Sci. Innov. 2(2) 17-22, 2023

Length (FL), Total Length (TL) (Fig. 1) and Body Weight 
(BW). The meristic characteristics were the Anal Fin Ray 
count (AFR) and Dorsal Fin Ray count (DFR).

Statistical Analysis
Past 326b (Paleontological Statistics Software) was used 
to analyze the descriptive statistics such as the Minimum 

(Min.), Maximum (Max), Mean (X ̅), Standard Errors (SE), 
Standard Deviation (SD), Variance (V) and Coefficient of  
Variation (CV) of  each characters, and students’ T-test 
was run to compare between means of  each characters 
by recording the significant difference of  each character 
parameter recorded from both locations. 

Figure 1: Morphometric Measurements Of  Pellonula Leonensis Used For Study

RESULTS AND DISCUSSION
Morphological characteristics of  P.  leonensis from Isaba 
Creek and New Calabar River. A total of  782 individuals 
were sampled, 614 individuals from Isaba River and 168 
from New Calabar River (Table 1). The range of  mean 
(X ̅), Standard Error (SE), Standard Deviation (SD), 
Variance (V), and Coefficient of  Variation (CV) of  the 
morphological characters of  P. leonensis are shown in 
Table 2. The size range of  TL and weight respectively 
of  3.70-8.52cm (X ̅=5.14±0.034cm) and 0.20-3.40g (X 
̅=0.75±0.022g) for ISABA Creek population and 6.5-9.80 
cm (X ̅=8.35±0.06cm) and 1.7-7.30 g (X ̅=3.84±0.083g) 
for New Calabar River population were observed. It can 
be seen that individuals from the New Calabar River 
possessed higher comparative range and mean values 
for each character relative to Isaba Creek. For all 19 
morphometric characters evaluated, 17 were significantly 
different between the Isaba Creek and the New Calabar 

River (p<0.05), except for the PFL and PvFL (p>0.05).
Meristic characteristics of  P. leonensis from Isaba River 
and New Calabar River
Table 3 shows the descriptive statistics for the meristic 
characteristics of  P.  leonensis from Isaba Creek and 
New Calabar River. The range of  Mean (X ̅) Standard 
Error (SE), Standard Deviation (SD), Variance (V) and 
Coefficient of  variation of  meristic characters observed 
in P. leonensis. The AFR and DFR showed significant 
differences between the two water bodies (p<0.05). For 
Isaba River population, the Anal Fin Ray (AFR) has 
a Range count of  10-22, and a Mean value of  17.33 ± 
0.073, and the Dorsal fin Ray (DFR) has a Range count 
of  9-22, and a Mean value of  15.97 ± 0.085. While for 
the population of  New Calabar River, the Anal Fin Ray 
has a Range count of  10-25 and a Mean Value of  19.18 ± 
0.172, and the Dorsal Fin Ray has a Range count of  12-22 
and a Mean value of  16.89 ± 0.168.

Table 2: Summary Descriptive Statistics for the morphometric characteristics of  P. leonensis from Isaba Creek and 
New Calabar River

C
ha

ra
ct

er Isaba River (N=614) New Calabar River (N=168) Sig
Min Max  ±Se

Sd V

Cv Min Max  ±Se Sd V Cv t Uneq.
var. t

AFL 0.20 1.40 0.70 ± 
0.009 0.

23

0.
05 32.83 0.6 1.9 1.11 ± 

0.02
0.23 0.05 20.32 ** **



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Am. J. Life Sci. Innov. 2(2) 17-22, 2023

BD 0.50 2.85 1.10 ± 
0.011 0.

30

0.
09 26.99 1.2 2.6 1.83 ± 

0.020
0.26 0.07 14.32 ** **

CFL 0.30 1.80 0.77 ±
0.01 0.

33

0.
11 42.57 0.6 2.2 1.23 ± 

0.026
0.33 0.11 27.08 ** **

CP 0.20 0.90 0.44 ± 
0.004 0.

11

0.
01 24.13 0.4 5.00 0.67 ± 

0.027
0.36 0.13 52.85 ** **

DBPAF 1.2 5.00 2.21 ± 
0.031 0.

76

0.
58

34.46 2.4 4.1 3.23 ± 
0.028

0.36 0.13 11.06 ** **

DFL 0.60 2.20 0.67 ±
0.01 0.

27

0.
07

40.57 0.5 1.4 0.98 ± 
0.015

0.19 0.04 19.25 ** **

ED 0.2 1.5 0.40 ± 
0.005 0.

11

0.
01 27.89 0.35 0.65 0.49 ± 

0.003
0.05 0.002 9.15 ** **

HD 0.3 1.6 0.77 ± 
0.009 0.

22

0.
05 28.77 0.9 2.1 1.44± 

0.017
0.22 0.05 14.90 ** **

HL 0.4 2.00 1.03 ± 
0.011 0.

2

0.
08 26.56 1.00 2.2 1.61± 

0.019
0.24 0.06 14.91 ** **

PFL 0.05 1.15 0.11 ± 
0.002

0.
05

0.
00

2

43.56 0.09 0.15 0.10± 
0.0006

0.008

0.00006

7.61 N . 
Sig

#

PvFL 0.08 1.15 0.11 ±
0.002

0.
00

5

0.
00

2

43.41 0.1 0.15 0.10± 
0.0006

0.008

0.0006

7.56 N . 
Sig

N. Sig

PrDFL 1.1 3.6 2.16 ±
0.017

0.
43

0.
18

19.82 2.7 4.20 3.51± 
0.024

0.32 0.10 8.98 ** **

PrPFL 0.3 2.00 1.12 ±
0.012 0.

30

0.
09

26.81 1.10 2.50 1.73± 
0.263

0.26 0.07 15.24 ** **

PrPvFL 0.7 5.00 2.09 ±
0.021

0.
53

0.
28

25.27 2.3 4.1 3.35± 
0.025

0.33 0.11 9.74 ** **

PrOL 0.2 2.6 0.43 ±
0.011

0.
28

0.
08

66.58 0.4 0.9 0.54± 
0.006

0.08 0.006 14.50 ** **

SL 3.00 7.30 4.43 ±
0.03

0.
78

0.
69

17.48 5.2 8.5 6.90± 
0.047

0.60 0.36 8.74 ** **

FL 3.2 7.7 4.72 ±
0.033 0.

82

O
.6

7 17.29 5.6 8.7 7.28± 
0.05

0.65 0.42 8.92 ** **

TL 3.70 8.52 5.41 ±
0.034

0.
86

0.
74

15.92 6.5 9.80 8.35± 
0.06

0.71 0.50 8.50 ** **

BW(g) 0.20 3.40 0.75 ±
0.022

0.
56

0.
31

74.27 1.7 7.3 3.84 ±
0.083

1.08 1.16 28.04 **     **

Where, MIN=Minimum, MAX=Maximum,  = Mean, SE= Standard Error, SD= Standard Deviaton, V= Variance, CV= 
Coefficient of  Variation,  t=t-Test, **significant at p<0.05, #=p=0.05, N Sig= No Significant difference p>0.5



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Am. J. Life Sci. Innov. 2(2) 17-22, 2023

Table 3: SSummary Descriptive Statistics for the Meristic characteristics of  P.  leonensis from Isaba Creek and New 
Calabar River
CHRS Isaba River (N=614) New Calabar River (N=168) Sig

Min Max  ±Se Sd V Cv Min Max  ±Se Sd V Cv t Uneq.
var. t

AFR 10 22 17.33 ± 
0.073

2.11 4.45 13.21 12 22 16.89 
±0.166

2.23 4.97 11.63 ** **

DFR 9 22 15.97 ±
0.085

2.11 4.45 13.21 12 22 16.89±
0.166

2.16 4.65 12.77 ** **

Where, MIN=Minimum, MAX=Maximum,  = Mean, SE= Standard Error, SD= Standard Deviaton, V= Variance, 
CV= Coefficient of  Variation, t=t-Test **significant at p<0.05,  N Sig= No Significant difference

The morphometric and meristic characters of  P. leonensis 
from Isaba Creek and New Calabar River were observed 
and compared in this study. A total of  782 individuals 
were sampled in this study. The size range of  TL and total 
weight recorded for ISABA Creek population and New 
Calabar River population fall within the range reported by 
Ezenwaji and Offish (2003) and Ezenwaji (2004) for the 
Anambra River. Yao et al. (2015) also reported individual 
weight ranging from 0.26 g to 3.22 g, with an average of  
0.81 ± 0.44 g and length varying from 31.67 to 65.35 mm 
with an average of  43.38 ± 6.31 mm in Taabo Lake.
The result from this study clearly demonstrates the 
variations between the two populations. For all the 
characters evaluated, individuals from the population 
from New Calabar River were bigger than the population 
those from Isaba Creek. Kurniawan et al. (2020) detected 
highly significant morphometric difference in Osteochilus 
spilurus from two separate water bodies. Solomon et 
al., (2015) reported abundant significant variations in 
morphometric characters of  Clarias gariepinus from 
different populations. Factors responsible for the 
differences between populations observed in this study 
are many and varied, including environmentally induced 
morphological and meristic changes due to stressors or 
pollution (Kurniawan et al. (2020).  The two water bodies 
by their location in the Niger Delta have been under the 
influence of  illegal exploration and exploitation of  crude 
oil resulting in oil pollution of  the water bodies, which 
is one of  the causes of  serious damages to water quality. 
Disparity in levels of  exposure to these environmental 
stressors may underpin changes in phenotype and 
genotype that culminate in fish adaptation. Swain and 
Foote (1999) observed that the phenotypic variation in 
morphological characters and meristic count may not 
only be genetic but may be environmentally induced. 
 Krabbenhoft et al. (2009) described the environmental 
factors underlying the morphological changes as water 
clarity, water depth and flow, food availability and physical 
complexity. Environmentally induced differences can also 
include diet or feeding habit, resulting in within species 
morphological variations in fish (Ehlinger, 1988; Fermon 
and Cibert 1998; Parker et al., 2009). Morphological 

divergence and intraspecific difference induced by 
habitat are reported to be common in fishes. For 
example, alteration in shape and fins can be influenced 
considering whether the water body is lentic or lotic. 
Physical characteristics can determine evolutionary 
changes and ecological conditions can drive changes 
in the morphological characteristics of  resident fish 
populations (Haas et al., 2010). Secondly, fishing pressure 
and utilization differential may mount spatial pressure on 
populations in natural habitats resulting in pronounced 
morphological differences (Kurniawan et al. (2020 citing 
Yang et al., 2003). Thus, we assert that fishing intensity 
may be higher in Isaba Creek relative to New Calabar River.  
Geographic isolation is another reason for intraspecific 
morphometric differences. Over time isolation by 
distance and barriers to gene flow play major role in 
these differences. The NCR and ISC are connected to 
the Ocean at different points along the coastal waters of  
Nigeria, which has created an effective barrier to gene 
flow between the two populations. With DNA, more light 
could be shed from these species when these rivers and 
creeks came to be separated. 
Sexual dimorphism observed in some species can manifest 
in wide range of  morphometric differences between 
populations (Parker, 1992; Breder and Rosen. 1998; 
Kim et al., 2008; Im et al., 2016; Pramono et al., 2019). 
Therefore, we suggest that in the studies employing the 
use of  morphometric traits, individuals should identified 
by sex. This was not taken into cognizance in executing 
this research, which may account for the differences if  
sexual dimorphism exist in the species.  
The meristic counts showed a very clear difference 
between the samples from the two population. Although 
it has been established that the meristic characters are 
independent of  the fish size; hence, they should not 
change during growth (Strauss 1985). This study has 
shown that the population from Isaba Creek is far small 
in size than that from New Calabar River, this significant 
difference in size might be due to high level of  fishing of  
mostly immature stock from the Isaba Creek. However, 
the morphometric and meristic variations examined in 
this reports are preliminary and provide an insight into 



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Am. J. Life Sci. Innov. 2(2) 17-22, 2023

the population of  the same species from two different 
water bodies.

CONCLUSION
Studies on the basis of  morphometric traits with respect 
to aquaculture and potential aquaculture species and 
species of  interest to capture fisheries should be initiated 
with the aim of  determining sexual dimorphism. Such 
studies would be expedient and useful for developing 
conservation strategies and domestication programs. 
Conflict of  interest.
The authors confirm that this article content has no 
conflicts of  interest.

Acknowledgements
We thank Professor S.N. Dekae of  Department of  
Fisheries, Rivers State University of  Science and 
Technology, Rivers State for assisting with identification. 

REFERENCE
Breder, C. M. & Rosen, D. E. (1996). Modes of  

Reproduction in Fishes. Garden City, New York: 
Natural History Press. 

Ehlinger, T. J. & Wilson, D. S. (1988). Complex foraging 
polymorphism in blue- gill sunfish. Proceedings 
National Academy of  Sciences, USA, 85, 1878-82.

Ezenwaji, H. M. G. (2004). Length-weight relationships 
of  fishes from Anambra River, southeastern. Nigeria. 
Animal Research International,  1(1), 1-6.

Ezenwaji, H. M. G. & Offiah, F. N. (2003). The biology 
of  Pellonula leonensis Bouleenger, 1916 (Osteichchtyes: 
Clupeidae) in Anambra River, Nigeria. Journal of  
Biological Research and Biotechnology, 1(2), 33-50.

Fermon, Y. & Cibert, C. (1998). Ecomorphological 
individual variation in a 344 population of  
Haplochromis nyererei from the Tanzanian part of  
Lake Victoria. Journal of   Fish Biology, 53, 66–83. 

Gourène, G. & Teugels, G. G. (1991). Revision du 
genre Pellonula des eaux douces africaines (Pisces: 
Clupeidae). Ichthol. Explorat. Freshwat., 2, 213-225.

Gourène, G. &  Teugels, G.G (2003). The fresh and 
brackish water fishes of  West Africa Volume 1. In 
D. Paugy, C. Lévêque and G.G Teugels (Eds.), Coll. 
faune et flore tropicales 40. Institut de recherche 
de développement, Paris, France, Muséum national 
d’histoire naturelle, Paris, France and Musée royal de 
l’Afrique Central, Tervuren, Belgium, 457p.

Haas, T. C., Blum, M. J. & Heins, D. C. (2010). 
Morphological responses of  a stream fish to water 
impoundment, Biology letters 6(6), 803-806.

Ikomi, R. B. (1995). Studies on the ecology of  the clupeid 
(Pellonula leonensis Regan, 1917) in the River Warri 
(Niger Delta, Nigeria). Acta hydrobiologica, 35, 381-398.

Im, J. H., Gil, H. W., Lee, T. H., Kong, H. J., Ahn, C. M., 
Kim, B. S., Kim, D. S., Zhang, C. I. & Park, I. S. (2016). 
Morphometric Characteristics and Fin Dimorphism 
between Male and Female on the Marine Medaka, 
Oryzias dancena. Development and Reproduction, 20(4), 

331-347.
Kim, Y., Zhang, C., In-Seok, P., Jonghun, N. & Paul 

O. (2008). Sexual dimorphism in morphometric 
characteristics of  Korean Chub Zacco koreanus 
(Pisces, Cyprinidae). Journal of  Ecology and Environment, 
31(2), 107-113.

Kingdom, T. & Allison, M. E. (2007b). Length–weight 
relationships and condition factor of  Pellonula 
leonensis in the lower Nun River, Niger Delta, Nigeria. 
International Journal of  Tropical Agriculture and Food 
Systems, 1(4), 330-334.

Kingdom, T. & Allison, M. E. (2009). Aspects of  the 
Reproductive Biology of  Pellonula leonensis in the 
Lower Nun River, Niger Delta. Current Research Journal 
of  Biological Sciences, 1(3), 68-71.

Kingdom, T. A. & Allison, M. E. (2007a). Abundance and 
gill net selectivity of  Pellonula leonensis in the Lower 
Nun River, Niger Delta, Nigeria. African Journal of  
Biotechnology, 6(20), 2419-2423.

Krabbenhoft, T. J., Collyer, M. L. & Quattro, J. M. (2009). 
Differing evolutionary patterns underlie convergence 
on elongate morphology in endemic fishes of  Lake 
Waccamaw, North Carolina. Biological Journal of  the 
Linnaen Society, 98, 626-645.

Kurniawan, A., Hariati, A M., Kurniawan, A, Darmawan, 
A. & Wiadnya, D. G. R. (2020). Morphometric 
comparison of  Osteochilus spilurus (Bleeker 1851) 
from Bangka and Belitung Island, Indonesia. IOP 
Conf. Series: Earth and Environmental Science, 493 
(2020) 012024.

Lowe-McConnell, R. T. H. (1987). Ecological studies in 
tropical fish communities. Cambridge University Press, 
382.

Parker, A. D, Stepien, C. A., Sepulveda-Villet, O. 
J,.  Ruehl, C. B. & Uzarski, D. G. (2009). Interplay 
of  morphology, habitat, resource use, and genetic 
relationships in young yellow perch. Transactions of  
American Fisheries Society, 138, 899-914.

Parker, G. A. (1992). The evolution of  sexual size 
dimorphism in fish. Journal of  Fish Biology, 41, 1-20.

Pramono, T. B., Arfiati, D., Widodo, M. S. & Yanuhar, U. 
(2019). Sexual dimorphism in morphometric characters 
of  Mystus singaringan from Klawing River in Central 
Java, Indonesia: Strategic instruction for conservation 
development. Biodiversta, 20(4), 1133-1139. 

Reid, G. M. G & Sydenham, D. H. J. (1979). A checklist 
of  lower Benue river (West Africa). Journals of  Natural 
History 13, 41-67.

Solomon, S. G, Okomoda, V. T. & Ogbenyikwu, A. I. 
(2015). Intraspecific morphological variation between 
cultured and wild Clarias gariepinus (Burchell) (Clariidae, 
Siluriformes) – Arch Polish Fisheries 23, 53-61.

Strauss, R. E. (1985). Evolutionary allometry and 
variation in body form in the South American catfish 
genus Corydorus (Callichthydae). Systematic Biology, 34, 
381-396.

Swain, D. & Foote, C. J. (1999). Stocks and chameleons: 
the use of  phenotypic variation in stock identification. 



Pa
ge

 
22

https://journals.e-palli.com/home/index.php/ajlsi

Am. J. Life Sci. Innov. 2(2) 17-22, 2023

Fishery Research, 43, 113-128.
Teugels, G. G., Reid, G. M. G. & King, R. P. (1992). 

Fishes of  the cross river basin (Cameroon Nigeria): 
Taxonomy, Zoogeography, Ecology and conservation. 
Annules Sciences Zoologues, 266, 1-732.

Turner, G. F. (1994). Lake Kainji Fisheries Statistic and 
Stock Assessment. Nigerian/German (GTZ) Kainji 

Fisheries Promotion Project., 0.
Yao, A. A., DA Costa, K. S. & Dietoa, Y. M. (2015). Small 

pelagic fish Pellonula leonensis Boulenger, 1916 (Pisces; 
Clupeidae) fishery in Taabo Lake: Typology, yield and 
socio- economic characteristics. International Journal of  
Fisheries and Aquatic Studies, 3(1), 392-399.


