Patterns of Body Shape Diversity and Evolution in Intertidal and Subtidal Lineages of Combtooth Blennies (Blenniidae)

Abstract

Marine intertidal zones can be hasher and more dynamic than bordering subtidal zones, with extreme and temporally variable turbulence, water velocity, salinity, temperature, and dissolved oxygen levels. Contrasting environmental conditions and ecological opportunities in subtidal versus intertidal habitats may generate differing patterns of morphological diversity. In this study we used phylogenetic comparative methods, measurements of body length, and two-dimensional landmarks to characterize body shape and size diversity in combtooth blennies (Ovalentaria: Blenniidae) and test for differences in morphological diversity between intertidal, subtidal, and supralittoral zones. We found that subtidal combtooth blennies have significantly higher body shape disparity and occupy a region of morphospace three times larger than intertidal lineages. The intertidal morphospace was almost entirely contained within the subtidal morphospace, showing that intertidal combtooth blennies did not evolve unique body shapes. We found no significant differences in body size disparity between tidal zones, no correlations between body shape and tidal zone or body size and tidal zone, and no body shape convergence associated with tidal zone. Our findings suggest that a subset of combtooth blenny body shapes are suitable for life in both subtidal and intertidal habitats. Many species in regions of morphospace unique to subtidal combtooth blennies exhibit distinct microhabitat use, which suggests subtidal environments promoted morphological diversification via evolutionary microhabitat transitions. In contrast, limited intertidal body shape diversity may be due to strong selective pressures that constrained body shape evolution and environmental filtering that prevented colonization of intertidal zones by certain subtidal body shapes.

Clarifying the taxonomy of some cryptic blennies (Blenniidae) in their native and introduced range

“…In addition, the life history traits of Omobranchus species could also have favoured the differentiation of O. punctatus s.s, O. dispar, and O. sewalli. The species of this genus are small, benthic inhabitants of intertidal zones and tide pools in coastal marine and estuarine ecosystems 17,20,24,61,62 . They are considered as permanent residents, showing a strong site fidelity during most of their life 20,21,27,61,63,64 .…”

Fungal Diversity and Its Relationship with Environmental Factors in Coastal Sediments from Guangdong, China

“…As the interface between land and sea, the coastal region not only provides many natural resources and facilities for human beings but also has a significant impact on nutrient cycling, decomposition, biodiversity conservation, and pollutant degradation in the ocean [ 1 ]. Moreover, the coastal region accumulates nutrients, heavy metal pollutants, and organic pollutants, and there are frequent changes in the coastal environment (such as salinity, dissolved oxygen, and nutrient content) caused by tidal movement, resulting in a much greater diversity of microbial communities in coastal sediments than in other sediments [ 2 ].…”