Resemblances in the early development of two sea urchins: Toxopneustes roseus (Euechinoidea: Echinacea) and Rhyncholampas pacificus (Euechinoidea: Irregularia) from different habitats in the southern Mexican Pacific

Dev Biol. 2023 Apr 19;499:1-9. doi: 10.1016/j.ydbio.2023.04.005. Online ahead of print.ABSTRACTSea urchins play a key role in the marine environment, contributing to maintain a balance in benthic ecosystems. Toxopneustes roseus acts as a regulator of rhodolith beds and is a key species as a bioturbation promoter, while Rhyncholampas pacificus moderates the detritus content of sediment through various mechanisms and contributes to accelerating the circulation of organic matter. However, nothing is known about their early development, so the objective of this research is to characterize the embryonic and larval development of specimens of the two species from the southern Mexican Pacific and identify the causes that produce their differences. The embryonic development of T. roseus lasted approximately 20 ​h; the echinopluteus larva appeared at 23 ​h and culminated in around 12 days with an eight-armed larva. Metamorphosis was reached at 18 days. The embryonic development of R. pacificus lasted about 15 ​h; the larva emerged at 20 ​h and culminated in about two days with an eight-armed larva. The metamorphosis was completed in 9 days. The reproductive output of both species determines their development time and the structure of their larvae; therefore, the energy of R. pacificus is invested in reaching metamorphosis earlier to ensure that its larvae, which are not very abundant, settle and recruit to the population. Regarding T. roseus, the longest permanence in the plan...
Source: Developmental Biology - Category: Biology Authors: Source Type: research