Schematic illustrations of seagrass members of the four different families. Cymodoceaceae: (a) Cymodocea serrulata, (b) Halodule pinifolia, (c) Halodule uninervis, (d) Halodule wrightii. Hydrocharitaceae: (e) Halophila decipiens, (f) Halophila ovalis, (g) Halophila ovata, (h) Halophila beccarii. Zosteraceae: (i) Zostera marina, (j) Zostera noltii. Posidoniaceae: (k) Posidonia australis (source of the single schemes: http://ian.umces.edu/symbols/).