Pre-invasion biological baselines for native fish and bivalves from a southern Mediterranean coastal lagoon: El Mellah, Algeria

Species	n	Sampling period	Collection methods
A. anguilla	103	January–May	Fyke nets
M. cephalus	122	July–October	Fish weir
C. auratus	68	July–September	Gillnets
C. glaucum	448	January–December	Hand collection
R. decussatus	451	January–December	Hand collection

Table 2

Summary statistics on measured variables of fish from El Mellah lagoon.

Species	n	TL (cm)				W (g)
Species	n	Range	Mean	SD	Median	Range	Mean	SD	Median
A. anguilla	103	28.2–66	43.72	7.65	43	34.72–484.27	146.59	85.80	122.2
M. cephalus	122	24.1–55.9	42.34	4.93	42.6	123.54–1820.5	817.76	276.91	785.2
C. auratus	68	17.7–34.4	26.21	3.36	25.9	73.1–325.2	177.78	76.22	181.2

[i] SD, standard deviation; TL, total length (cm).

[ii] n: number of individuals; W: total weight (g).

Table 3

Summary statistics on measured variables of bivalves from El Mellah lagoon.

Species	n	SL (mm)				W (g)
Species	n	Range	Mean	SD	Median	Range	Mean	SD	Median
C. glaucum	448	19–47	33.21	4.28	33	2.24–33.49	13.45	4.68	13.27
R. decussatus	451	30–66	45.65	7.3	46	5.34–54.52	19.09	9.37	18.03

[i] SD, standard deviation; SL, total shell length (mm).

[ii] n: number of individuals; W: total weight (g).

Table 4

LWR parameters of studied species.

Species	n	Equation	a	95% CI a	*SE b*	95% CI b	p (regression)	R²	p (t-test, b = 3)	Growth pattern
A. anguilla	103	log W = −3.0084 + 3.1223 log TL	0.0010	0.0004–0.0026	0.1292	2.866–3.379	<0.0001	0.853	> 0.05	I
M. cephalus	122	log W = −1.6900 + 2.8191log TL	0.0204	0.0104–0.0400	0.0908	2.639–2.999	<0.0001	0.889	<0.05	A –
C. auratus	68	log W = −2.3175 + 3.1984 log TL	0.0048	0.0015–0.0155	0.1792	2.841–3.556	<0.0001	0.828	>0.05	I
C. glaucum	448	log W = −2.7871 + 2.5628 log SL	0.0016	0.0012–0.0023	0.0469	2.471–2.655	<0.0001	0.870	<0.05	A –
R. decussatus	451	Log W = −3.7991 + 3.0399 log SL	0.0002	0.0001–0.0002	0.0271	2.987–3.093	<0.0001	0.966	>0.05	I

[i] 95% CI, 95% confidence interval; LWR, length-weight relationship; SE, standard error; SL, total shell length; TL, total length.

[ii] n: number of individuals; W: total weight; R²: coefficient of determination; I: isometric growth; A–: negative allometry.

Table 5

Fulton's condition factor (K) of fish from El Mellah lagoon.

Species	n	Range	Mean	SD	Median
A. anguilla	103	0.08–0.29	0.16	0.04	0.15
M. cephalus	122	0.82–1.63	1.05	0.13	1.04
C. auratus	68	0.67–1.42	0.94	0.18	0.88

Table 6

Condition index (CI) of bivalves from El Mellah lagoon.

Species	n	Range	Mean	SD	Median
C. glaucum	448	1.17–7.68	4.00	1.12	4.01
R. decussatus	451	3.92–20.41	11.71	2.16	11.63

References

Authors

Metrics

Articles in this issue

DOI: https://doi.org/10.26881/oahs-2026.1.28 | Journal eISSN: 1897-3191 | Journal ISSN: 1730-413X

Journal RSS Feed

Language: English

Page range: 377 - 386

Submitted on: Jul 28, 2026

Accepted on: Sep 4, 2026

Published on: Oct 10, 2026

Published by: University of Gdańsk

In partnership with: Paradigm Publishing Services

Publication frequency: 4 issues per year

Keywords:

invasion baseline,

length-weight relationship,

fish condition factor,

bivalve condition index,

Related subjects:

© 2026 Lamia Bensaâd-Bendjedid, Imene Ladjama, Hassen Touati, published by University of Gdańsk
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Volume 55 (2026): Issue 3 (September 2026)

Pre-invasion biological baselines for native fish and bivalves from a southern Mediterranean coastal lagoon: El Mellah, Algeria

Figures & Tables

Figure 1

Table 1

Table 2

Table 3

Table 4

Table 5

Table 6

Paradigm

My account