Table 1 Diversity indices (richness = number of sessile phenotypes, H’ = Shannon, D = Simpson) and evenness accounting for sessile invertebrates for investigated as well as reference biodiversity hotspots based on literature data.

Phyllophora crispa

NW Mediterranean

223

9^{a,b,c,e,f,m,p,r,s}

0.6969

2.209

0.2693

Present study

Posidonia oceanica

NW Mediterranean

179

7^{a,b,c,f,m,p,s}

0.7581

2.128

0.2900

Present study

Posidonia oceanica

S Mediterranean

33

5^a,b,f,p,s

0.8706

2.021

0.2519

Mabrouk et al. (2014)¹⁰⁶

Coralligenous reefs

NW Mediterranean

55

6^a,b,c,f,p,s

0.8070

2.086

0.2539

Verdura et al. (2019)¹⁰⁷

Coralligenous reefs

Mediterranean

786^t

7^{a,b,c,f,m,p,s}

0.9418

2.644

0.1731

Ballestros (2006)¹⁰⁸

Cystoseira zosteroides

NW Mediterranean

78

6^a,b,c,f,p,s

0.7574

1.958

0.3004

Ballestros et al. (2009)¹⁰⁹

Coral reef

SW Indian Ocean

457

5^a,c,f,m,s

0.8765

2.035

0.2789

Cleary et al. (2016)¹¹⁰

Coral reef turf algae

W Indian Ocean

48^u

2^p,m

0.9950

0.995

0.4929

Milne and Griffiths (2014)¹¹¹

Coldwater coral reef

N Atlantic Ocean

213

7^{a,b,c,f,m,p,s}

0.9523

2.673

0.1653

Mortensen and Fossa (2006)¹¹²

Coldwater coral reef

N Atlantic Ocean

77

4^a,b,c,s

0.8062

1.612

0.3585

Henry et al. (2010)¹¹³

Mangrove forest

Caribbean Sea

54

6^a,b,c,m,p,s

0.7494

1.937

0.2970

Farnsworth and Ellison (1996)¹¹⁴

Kelp forest

NE Pacific Ocean

79^v

6^a,b,c,m,p,s

0.9456

2.444

0.1912

Graham (2004)¹¹⁵

Antarctic hard bottom

Weddell Sea

608^w

6^a,b,c,f,m,s

0.8500

2.197

0.2803

Gutt et al. (2000)¹¹⁶

Halimeda bioherm

Coral Sea

474^w

5^a,b,c,m,s

0.6965

1.617

0.4202

McNeil et al. (2021)³⁹