Scientific Article
ISSN 1678-2305 online version
BOLETIM DO INSTITUTO DE PESCA
Sousa et al. Bol. Inst. Pesca 2019, 45(2): e396. DOI: 10.20950/1678-2305.2019.45.2.396 1/8
GROWTH PARAMETERS AND YIELD PER RECRUIT ANALYSIS FOR
THE ARMOURED CATFISH Pterygoplichthys pardalis SAMPLED IN
THE LOW REACH OF THE AMAZONAS RIVER
ABSTRACT
Armoured catfish Pterygoplichthys pardalis is an endemic fish from the Amazon basin (Brazil) and
currently is the top ten target species in the regional fisheries. A total of 1,200 samples were collected
monthly from March 2011 to February 2012 with an average length of 28 ± 2.57 cm and average weight
of 441.57 ± 103.37 g. The growth stock parameters for this species (W
t
= 0.431227 * L
t
2.08637
; M = 0.93
year
-1
; F-
Estimated
= 0.91 year
-1
; F-
10
= 3.02 year
-1
; A
0.95
= 7.31 years; K = 0.41 year
-1
; T
r
= T
c
= 1.92 years; L
c
= 21.14 cm; L
= 38.85 cm; W
= 869.76 g) and exploitation rate (E-
Estimated
= 0.50; E-
10
= 0.80) reveal that
its stocks are not being overfished in the study area. The baseline information obtained in this study
can help support fisheries management strategies of P. pardalis, especially regarding the potential
implementation of a policy to increase landings of individuals larger than 22.3 cm length. However,
before making a final decision, it is necessary to carefully examine the available information and
evidence aimed at sustainable fishing management and conservation of their stocks, which is of great
cultural, social and economic importance for Amazonian peoples.
Keywords: acarí-bodó; Amazon basin; fisheries; native fish; yield per recruit; Tupinambarana Island.
PARÂMETROS DE CRESCIMENTO E ANÁLISE DA TAXA DE RECRUTAMENTO
DO PEIXE CASCUDO Pterygoplichthys pardalis PESCADO NO TRECHO DO
BAIXO RIO AMAZONAS
RESUMO
O peixe cascudo Pterygoplichthys pardalis é uma espécie nativa da bacia Amazônica (Brasil), e
atualmente está entre as dez espécies alvo nas pescarias regionais. Exemplares dessa espécie
foram obtidos entre março de 2011 e fevereiro de 2012, em coletas mensais, agregando
1.200 espécimes, com média de comprimento de 28 ± 2,57 cm, e média de peso de 441,57 ± 103,37 g.
Os parâmetros do crescimento do estoque do peixe cascudo (W
t
= 0,431227 * L
t
2,08637
; M = 0,93 ano
-1
;
F-
Estimado
= 0,91 ano
-1
; F-
10
= 3.02 ano
-1
; A
0,95
= 7,31 anos; K = 0,41 ano
-1
; T
r
= T
c
= 1,92 anos;
L
c
= 21,14 cm; L
= 38,85 cm; W
= 869,76 g) e taxa de explotação (E-
Estimada
= 0,50; E-
10
= 0,80)
revelaram que a espécie não está em situação de sobre pesca na área do estudo. As informações
obtidas neste estudo, são pioneiras e gerais, e podem embasar medidas para a gestão da pesca,
especialmente com a possibilidade de aumentar o esforço de captura sobre os indivíduos de
P. pardalis com comprimento em torno de 22,3 cm. No entanto, é necessário ter cautela durante
as tomadas de decisões, objetivando o manejo sustentável da atividade pesqueira e a conservação
de seus estoques, que são de grande importância cultural, social e econômica para as populações
amazônicas.
Palavras-chave: acarí-bodó; pescarias amazônicas; Bacia Amazônica; peixe nativo; taxa por recruta;
Ilha Tupinambarana.
INTRODUCTION
The Amazon basin is the largest freshwater basin in the world (ANA, 2018), consisting
of a huge and complex system of rivers with adjacent floodplains (Junk et al., 2007).
This ecosystem hosts the highest ichthyofauna diversity on Earth (Reis et al., 2016),
totaling approximately 2,500 fish species already described (Junk et al., 2007;
Lévêque et al., 2008). Consequently, this abundance of fish is exploited by more than
Raniere Garcez Costa Sousa
1
Cidiane Melo Oliveira
1
Igor Rechetnicow Alves Sant’Anna
2
Bruce Gavin Marshall
3
Carlos Edwar de Carvalho Freitas
2
1
Universidade Federal de Rondônia, Departamento
de Engenharia de Pesca, Programa de Pós-graduação
em Ciências Ambientais, Rua da Paz, 4376, CP 32,
CEP 76916-000, Presidente Médici, RO, Brasil.
E-mail: ranieregarcez@unir.br (corresponding author).
2
Universidade Federal do Amazonas, Departamento
de Ciências Pesqueiras, Avenida General Rodrigo
Octávio Jordão Ramos, 3000, Coroado I, Campus
Universitário, CEP 69077-000, Manaus, AM, Brasil.
3
University of British Columbia, Norman B. Keevil
Institute of Mining Engineering, 6350 Stores Road,
V6T 1Z4, Vancouver, BC, Canada
Received: May 02, 2018
Approved: January 02, 2019
GROWTH PARAMETERS AND YIELD PER RECRUIT
Sousa et al. Bol. Inst. Pesca 2019, 45(2): e396. DOI: 10.20950/1678-2305.2019.45.2.396 2/8
330,000 fishers in the Brazilian Amazon basin (BRASIL, 2016),
both for subsistence and commercial means. These fisheries are
also important in terms of social, economic and cultural (traditional
practices) aspects for the riverine communities that inhabit the
banks of Amazonian rivers and lakes (Barthem and Fabré, 2004;
Isaac et al., 2015; Souza et al., 2015).
In the last four decades, the equilibrium between fisher
(resource user) and fish (exploited resource) has changed, with
the number of fishers increasing, while the number of fish has
decreased. Therefore, overexploitation has occurred with some
fish stocks, mainly popular commercial fish species like tambaqui
(Campos et al., 2015). Concomitantly, loss of fish habitat
predominantly caused by the construction of hydroelectric dam
installations, has intensified in recent years, thereby negatively
impacting fish stocks (Doria et al., 2017).
Amazonian fishery yields are strongly dependent on the seasonal
dynamics of the hydrological flood pulse (Garcez et al., 2017).
Specifically, the hydrological pattern has been shown to directly
affect the diversity and composition of fish assemblages (Souza et al.,
2015), whose abundances or scarcities ultimately dictate fisheries’
successes or failures (Souza et al., 2015; Garcez et al., 2017).
Several fish species present morphological adaptations to
survive in floodplain areas during the low water or drought season,
when environmental conditions are adverse. Consequently, these
characteristics allow certain fish assemblages to stay in these areas
throughout the entire annual hydrological period (Garcez and
Freitas, 2008). For example, some fish species that belong to the
Siluriformes family have taxonomical adaptations that allow the
individuals to survive in anoxic environments, which is the case of
the armored catfish Pterygoplichthys pardalis (Castelnau, 1855).
P. pardalis, known locally as acari-bodó by the riverine
communities, is a medium-sized fish that belongs to the Loricaridae
Family, reaching a maximum total length of approximately 49 cm
and 550 g of total weight (Neves and Ruffino, 1998; Jumawan
and Seronay, 2017). Acari-bodó is benthic in nature and occurs
exclusively in the Amazon basin (Weber, 1992), being found in
different aquatic habitats, including floodplain areas, lakes, and
on the margins of black, clear and white waters rivers. It has
detritivorous feeding habits, feeding mainly on amorphous organic
material, sediments and algae (Santos et al., 2006). P. pardalis
also has air-breathing capability, with a high level of anaerobic
metabolism, and can live in water with low dissolved oxygen
(Bailey et al., 1997). P. pardalis does not migrate and shows an
equilibrium reproductive strategy (Winemiller, 1989), which results
in a prolonged reproductive period, spanning approximately eight
months of every year (Neves and Ruffino, 1998).
P. pardalis is among the top ten fish species consumed by people
in the Central Amazon region (Cerdeira et al., 1997; Neves and
Ruffino, 1998), as it’s a very tasty fish with high protein quality and
low fat (Ferreira et al., 1998). Its muscle tissue is used to produce
fish-meal powder, locally known as “piracuí”, which is widely
consumed by Amazonian riverine communities (Lourenço et al.,
2011). Due to its popularity as a food fish, as well as its ability
to survive for more than 30 hours outside of the water (Val and
Almeida-Val, 1995), Amazonian artisanal fishermen catch and
commercialize live specimens of acari-bodó at marketplaces in urban
centers, due to quick degradation after mortality (Lourenço et al.,
2011). Commercial landings of acari-bodó have been observed
in many cities along the Solimões-Amazonas River, including in
Parintins municipality in Amazonas State, mainly for consumption
purposes (personal observation).
Many studies have investigated different aspects of P. pardalis,
including its reproductive biology (Neves and Ruffino, 1998;
Winemiller, 1989), air-breathing capability (Bailey et al., 1997),
its potential for use in developing commercial food products,
(Lourenço et al., 2011), and also as an environment bio-indicator
species (Freitas and Siqueira-Souza, 2009). However, there is
not one study that has investigated the populations dynamics of
P. pardalis, especially in relation to fish stocks and impacts from
fishing. Furthermore, the lack of fisheries data compromises the
ability to implement conservation management strategies, which
also need to take into consideration both socioeconomic and
ecological importance of this species for Amazonian populations.
In this way, the present research aims to estimate the population
dynamics and growth parameters of P. pardalis compiled from
seasonal fish landing data in Parintins municipality, in order to
try and determine the sustainability of the fishery in that region
and support future management plans for its conservation.
METHODS
Study area
The present research was conducted in the small city of Parintins
(Tupinambarana island, 02º 37’ 42” S and 56º 44’ 09” W), which
is situated on the southern margin of the Amazon River in eastern
Amazonas State, Brazil (Figure 1). The municipality of Parintins
encompasses an area of 5,952 km
2
, which reported a population
of 113,832 people in 2016 (IBGE, 2017).
Sample collections
Samples of P. pardalis were collected monthly from March
2011 to February 2012 (n = 100 per month) from commercial
fish landings at Bagaço and Zezito Assayag markets in the city
of Parintins. Fish specimens were preserved in coolers with ice
and transported to the Fish Ecology Laboratory at the Federal
Institute of Education, Science and Technology of Amazonas
State, where measurements of total length (L
t
- cm) and total
weight (W
t
- g) were taken.
Data analyses
All of the biometric values (L
t
and W
t
) of P. pardalis individuals
were compiled using Statistica 9.0 software (STATSOFT Inc., 2009)
to analyze the length-weight relationship. This relationship is
determined from a nonlinear regression using Levenberg-Marquardt´s
algorithm (Fan, 2013), which consider the parameters “a” (curve
intercept) and “b” (allometry coefficient), as displayed in the
equation of W
t
= a*L
t
b
(Le Cren, 1951), where W
t
is the total
weight and L
t
is the total length. Consequently, the biometric
dataset was then employed in the FISAT II analysis (FAO-ICLARM