Shell Shape Analysis and Spatial Allometry Patterns of Manila Clam (Ruditapes philippinarum) in a Mesotidal Coastal Lagoon

Table 2

NPCA synthetic descriptors.

Selected principal components	Description	Shape tendency
Character1	Individuals presenting high values for 𝑆𝑀/𝐿, 𝑆𝑀/𝐻, 𝑊/𝐿 ratios, high indices related to ventral circle and reference ellipse	Heavy shells regarding linear measures and high values of width related to length-globular individuals
Character2	𝐿, 𝐻/𝐿, EIL, CIL and two of the weight ratios (𝑆𝑀/𝐻 and 𝑆𝑀/𝑊): the higher the indices of related mass and length, the less the clam presents a round form (lateral view)	Heavy shells regarding linear dimensions but associated to high values of lengths
Character3	Shells with high 𝐻/𝐿 ratio and lateral indices, by opposition to low 𝑊/𝐿 and 𝑊/𝐻 ratios	Round shells (lateral view) and little width related to length and height