
Fig. 1.
Collection sites of Sarpa salpa (n=114) from the Central coast of Algeria [Created by https://www.simplemappr.net. Accessed June 04, 2023]

Fig. 2.
The Digenean parasites infecting Sarpa salpa from the Central coast of Algeria: (a) Lepocreadium album (Ventral view), (b) Centroderma spinosissima (Ventral view), (c) Mesometra orbicularis (Ventral view), (d) Mesometra brachycoelia (Ventral view), (e) Wardula capitellata (Ventral view), (f) Elstia stossichianum (Ventral view), (g) Robphildollfusium fractum (Lateral view). (Ph) Pharynx, (OB) Oesophageal bulb, (T) Testes, (O) Ovary, (M) Metraterm, (CP) Cirrus pouch, (C) Ceaca, (VS) Ventral sucker, (OS) Oral sucker, (VF) Vitellarium follicles, (E) Eggs
Table 1.
Digenea species composition in Sarpa salpa (n = 114) from the Algerian Central coast
| Digenea species | Number of infected fish | Number of parasites | Prevalence % | Mean abundance | Mean intensity | Range of intensity | Importance value |
|---|---|---|---|---|---|---|---|
| Lepocreadium album | 1 | 30 | 0.88 | 0.26 | 30.00 | 30 | Satellite |
| Centroderma spinosissima | 4 | 13 | 3.51 | 0.11 | 3.25 | 1 – 8 | Satellite |
| Elstia stossichianum | 35 | 170 | 30.70 | 1.49 | 4.86 | 1 – 18 | Satellite |
| Mesometra brachycoelia | 55 | 1495 | 48.25 | 13.11 | 27.18 | 1 – 167 | Secondary |
| Mesometra orbicularis | 93 | 1565 | 81.58 | 13.73 | 16.83 | 1 – 115 | Core |
| Wardula capitellata | 11 | 21 | 9.65 | 0.18 | 1.91 | 1 – 4 | Satellite |
| Robphildollfusium fractum | 101 | 5428 | 88.60 | 47.61 | 53.74 | 1 – 242 | Core |
Table 2.
Species composition of the Digenea communities infecting Sarpa salpa.
| n | P % | ||
|---|---|---|---|
| 1 (10.28 %) | R. f | 9 | 8.41 |
| M. o | 2 | 1.87 | |
| 2 (28.97%) | R. f - M. o | 24 | 22.43 |
| R. f - M. b | 2 | 1.87 | |
| R. f - E. s | 2 | 1.87 | |
| M. o - M. b | 1 | 0.93 | |
| M. o - E. s | 1 | 0.93 | |
| M. o - W. c | 1 | 0.93 | |
| 3 (36.45%) | R. f - M. o - M. b | 29 | 27.10 |
| R. f - M. o - E. s | 7 | 6.54 | |
| R. f - M. o - W. c | 1 | 0.93 | |
| R. f - E. s - C. s | 1 | 0.93 | |
| M. o - W. c - E. s | 1 | 0.93 | |
| 4 (18.96%) | R. f - M. o - M. b - E. s | 15 | 14.02 |
| R. f - M. o - M. b - W. c | 3 | 2.80 | |
| R. f - M. o - E. s - W. c | 2 | 1.87 | |
| 5 (5.61) | R. f - M. o - M. b - E. s - C. s | 3 | 2.80 |
| R. f - M. o - M. b - E. s - W. c | 2 | 1.87 | |
| R. f - M. o - E. s - L. a - W. c | 1 | 0.93 |
[i] P, prevalence; n, number of hosts; C. s, Centroderma spinosissima; E. s, Elstia stossichianum; M.b, Mesometra brachycoelia: M. o, Mesometra orbicularis; L. a, Lepocreadium album; R. f, Robphildollfusium fractum; W. c, Wardula capitellata
Table 3.
Data relative to weight classes of Sarpa salpa.
| Weight classes | 73.5 – 170.42 g | 170.43 – 267.35 g | 267.36 – 364.28 g | 364.29 – 461.21 g | 461.22 – 558.14 g | 558.15 – 655.07 g | 655.08 – 752 g | |
|---|---|---|---|---|---|---|---|---|
| Host examined | 18 | 37 | 21 | 22 | 12 | 2 | 2 | |
| Host infected | 17 | 35 | 20 | 22 | 9 | 2 | 2 | |
| Number of parasites | 725 | 2456 | 1970 | 2663 | 591 | 171 | 146 | |
| Number of parasites per species | L. album | 0 | 30 | 0 | 0 | 0 | 0 | 0 |
| C. spinosissima | 0 | 1 | 8 | 4 | 0 | 0 | 0 | |
| E. stossichianum | 13 | 46 | 66 | 39 | 6 | 0 | 0 | |
| M. brachycoelia | 153 | 600 | 367 | 263 | 60 | 6 | 46 | |
| M. orbicularis | 190 | 450 | 452 | 406 | 43 | 13 | 11 | |
| W. capitellata | 14 | 2 | 5 | 0 | 0 | 0 | 0 | |
| R. fractum | 355 | 1327 | 1072 | 1951 | 482 | 152 | 89 | |
Table 4.
Data relative to length classes of Sarpa salpa.
| Length classes | 17.5 – 20.40 cm | 20.41 – 23.31 cm | 23.32 – 26.22 cm | 26.23 – 29.13 cm | 29.14 – 32.04 cm | 32.05 – 34.95 cm | 34.96 – 37.86 cm | |
|---|---|---|---|---|---|---|---|---|
| Host examined | 5 | 18 | 33 | 17 | 30 | 6 | 5 | |
| Host infected | 5 | 16 | 32 | 16 | 29 | 5 | 4 | |
| Number of parasites | 278 | 947 | 2492 | 1147 | 3187 | 354 | 317 | |
| Number of parasites per species | L. album | 0 | 0 | 30 | 0 | 0 | 0 | 0 |
| C. spinosissima | 0 | 0 | 1 | 8 | 4 | 0 | 0 | |
| E. stossichianum | 1 | 22 | 46 | 44 | 51 | 6 | 0 | |
| M. brachycoelia | 112 | 165 | 667 | 165 | 288 | 46 | 52 | |
| M. orbicularis | 70 | 164 | 424 | 400 | 436 | 47 | 24 | |
| W. capitellata | 7 | 7 | 7 | 0 | 0 | 0 | 0 | |
| R. fractum | 88 | 589 | 1317 | 530 | 2408 | 255 | 241 | |
Table 5.
Relationship between the species prevalence and the host's weight and length using the Chi square test.
| Weight (g) | Total length (cm) | |||
|---|---|---|---|---|
| χ2 | p | χ2 | p | |
| Lepocreadium album | 0.136 | 0.910 | 2.476 | 0.871 |
| Centroderma spinosissima | 3.43 | 0.674 | 2.425 | 0.877 |
| Elstia stossichianum | 8.301 | 0.217 | 5.390 | 0.495 |
| Mesometra brachycoelia | 4.455 | 0.615 | 7.647 | 0.265 |
| Mesometra orbicularis | 4.825 | 0.566 | 2.967 | 0.813 |
| Wardula capitellata | 22.475 | 0.001* | 24.229 | 0.000* |
| Robphildollfusium fractum | 8.005 | 0.238 | 7.454 | 0.281 |
Table 6.
The Spearman's correlation test evaluating the mean abundance and mean intensity of species with the host parameters (weight and total length).
| Digenea | Mean abundance | Mean intensity | ||||||
|---|---|---|---|---|---|---|---|---|
| Weight (g) | Total length (cm) | Weight (g) | Total length (cm) | |||||
| rs | p | rs | p | rs | p | rs | p | |
| Lepocreadium album | −0.408 | 0.363 | −0.204 | 0.661 | −0.408 | 0.363 | −0.204 | 0.661 |
| Centroderma spinosissima | −0.374 | 0.408 | 0.039 | 0.933 | −0.374 | 0.408 | 0.039 | 0.933 |
| Elstia stossichianum | −0.667 | 0.102 | −0.143 | 0.76 | −0.523 | 0.229 | 0.036 | 0.939 |
| Mesometra brachycoelia | 0.000 | 1.000 | 0.179 | 0.702 | −0.643 | 0.119 | −0.857 | 0.014* |
| Mesometra orbicularis | −0.571 | 0.18 | −0.429 | 0.337 | −0.393 | 0.383 | −0.429 | 0.337 |
| Wardula capitellata | −0.867 | 0.012* | −0.906 | 0.005** | −0.788 | 0.035* | −0.896 | 0.006** |
| Robphildollfusium fractum | 0.536 | 0.215 | 0.786 | 0.036* | 0.464 | 0.294 | 0.75 | 0.052 |

Fig. 3.
Species accumulation curve used to evaluate the sampling effort of Sarpa salpa (n = 114) from the Central coast of Algeria and the number of species found.
Table 7.
Biodiversity parameters of the component community and infracommunity of Digenea species infecting Sarpa salpa from the Central coast, Algeria.
| Component community | Infracommunity | ||||||
|---|---|---|---|---|---|---|---|
| Species richness (S) | Shannon Diversity Index (H′) | Evenness Shannon-Winner (J) | Dominance Simpson (D) | Dominant species | Berger-Parker Index (BP) | Mean species richness (mean ± SD) | Mean number of parasites per host (mean ± SD) |
| 7 | 1.03 | 0.53 | 2.23 | R. fractum | 0.62 | 2.62 ± 1.21 | 76.37 ± 76.5 |