Khouloud BOUHALI, DERBAL F., KARA M. H.
Laboratoire Bioressources Marines, Université d’Annaba Badji Mokhtar, Algeria
E-mail: khouloud_bouhali@ymail.com
FIRST DATA ON THE BIOLOGY AND DYNAMICS OF THE
AMERICAN BLUE CRAB CALLINECTES SAPIDUS IN MELLAH
LAGOON, ALGERIA
Abstract
This study is a contribution to the knowledge of the biology and population structure of
an invasive American blue crab Callinectes sapidus Rathbun, 1896 (Decapoda:
Brachyura: Portunidae). A total of 525 individuals, represented by 312 females (38.9 <
CLf < 80.3 mm, 77 < WTf < 173 g) and 213 males (43.7 < CLm < 90.5, 80 < WTm <
175 g) was sampled between February 2021 and February 2022. The following
parameters were determined: size structure, sex ratio, reproductive period, size at first
sexual maturity, relationship between size and weight. The overall sex ratio was in
favour of females (SR = 0.68, ² = 18.66). This dominance was maintained during all
seasons, with the exception of Summer when the two sexes were numerically balanced.
The first ovigerous females appeared in May and became the majority in July (63.8%).
The size frequency distribution (LC) highlighted 5 different cohorts, which would
correspond to ages 1 to 5, with respectively 4.4 cm, 5.5 cm, 6.8 cm, 7.8 cm, 8.3 cm of
carapace length (CL). The CL / total body weight (TP) relationship resulted for both
sexes: W = 4.82 CL -163.7 (r2 = 0.493). Females reach their first sexual maturity at
7.05 cm.
Key-words: Callinectes sapidus, population structure, reproduction, Mellah lagoon, Algeria.
Introduction
The American blue crab Callinectes sapidus is native to the North Atlantic and
distributed from Nova Scotia, Maine and Massachusetts to Argentina, Bermuda and the
West Indies (Tavares, 2002). It was reported along the European Atlantic coast in the
year 1900 in France (Bouvier, 1901). In the Mediterranean, C. sapidus is an exotic
species reported for the first time in 1949 (Mizza, 1993). High fecundity, great
swimming ability and pronounced aggressiveness have favoured its establishment
(Millikin and Williams, 1984). In Algeria, C. sapidus was reported for the first time in
the mouth of Oued Zhor (Skikda) in 2019 (Benabdi et al., 2019). Hamida and Kara
(2021) and confirmed and documented its presence the same year in Mafragh Estuary
(El Tarf). The species developed a highly invasive population in Mellah lagoon since
2021 (Kara et Chaoui, 2021). This work provides the first information on the sexual
cycle and dynamics of C. sapidus in Mellah lagoon.
Materials and methods
This study was carried out in Mellah lagoon, which is characterized by a surface area of
865 ha, with an average depth of 3.5 m. Temperature and salinity in this lagoon vary
annually between 10–30.2°C and 25– 34.8‰, respectively (Draredja and Kara, 2004).
Crabs are fished with fyke nets (L = 8 m) placed at a depth of about 2.5 m where the
2nd Mediterranean Symposium on the Non-Indigenous Species (Genoa, Italy, 22-23 September 2022)
83
Laboratoire Bioressources Marines, Université d’Annaba Badji Mokhtar, Algeria
E-mail: khouloud_bouhali@ymail.com
FIRST DATA ON THE BIOLOGY AND DYNAMICS OF THE
AMERICAN BLUE CRAB CALLINECTES SAPIDUS IN MELLAH
LAGOON, ALGERIA
Abstract
This study is a contribution to the knowledge of the biology and population structure of
an invasive American blue crab Callinectes sapidus Rathbun, 1896 (Decapoda:
Brachyura: Portunidae). A total of 525 individuals, represented by 312 females (38.9 <
CLf < 80.3 mm, 77 < WTf < 173 g) and 213 males (43.7 < CLm < 90.5, 80 < WTm <
175 g) was sampled between February 2021 and February 2022. The following
parameters were determined: size structure, sex ratio, reproductive period, size at first
sexual maturity, relationship between size and weight. The overall sex ratio was in
favour of females (SR = 0.68, ² = 18.66). This dominance was maintained during all
seasons, with the exception of Summer when the two sexes were numerically balanced.
The first ovigerous females appeared in May and became the majority in July (63.8%).
The size frequency distribution (LC) highlighted 5 different cohorts, which would
correspond to ages 1 to 5, with respectively 4.4 cm, 5.5 cm, 6.8 cm, 7.8 cm, 8.3 cm of
carapace length (CL). The CL / total body weight (TP) relationship resulted for both
sexes: W = 4.82 CL -163.7 (r2 = 0.493). Females reach their first sexual maturity at
7.05 cm.
Key-words: Callinectes sapidus, population structure, reproduction, Mellah lagoon, Algeria.
Introduction
The American blue crab Callinectes sapidus is native to the North Atlantic and
distributed from Nova Scotia, Maine and Massachusetts to Argentina, Bermuda and the
West Indies (Tavares, 2002). It was reported along the European Atlantic coast in the
year 1900 in France (Bouvier, 1901). In the Mediterranean, C. sapidus is an exotic
species reported for the first time in 1949 (Mizza, 1993). High fecundity, great
swimming ability and pronounced aggressiveness have favoured its establishment
(Millikin and Williams, 1984). In Algeria, C. sapidus was reported for the first time in
the mouth of Oued Zhor (Skikda) in 2019 (Benabdi et al., 2019). Hamida and Kara
(2021) and confirmed and documented its presence the same year in Mafragh Estuary
(El Tarf). The species developed a highly invasive population in Mellah lagoon since
2021 (Kara et Chaoui, 2021). This work provides the first information on the sexual
cycle and dynamics of C. sapidus in Mellah lagoon.
Materials and methods
This study was carried out in Mellah lagoon, which is characterized by a surface area of
865 ha, with an average depth of 3.5 m. Temperature and salinity in this lagoon vary
annually between 10–30.2°C and 25– 34.8‰, respectively (Draredja and Kara, 2004).
Crabs are fished with fyke nets (L = 8 m) placed at a depth of about 2.5 m where the
2nd Mediterranean Symposium on the Non-Indigenous Species (Genoa, Italy, 22-23 September 2022)
83