A Mysterious World Revealed: Larval-Adult Matching of Deep-Sea Shrimps from the Gulf of Mexico

Carlos Varela,Heather Bracken-Grissom

doi:10.3390/d13100457

Abstract

The identification of deep-sea (>200 m) pelagic larvae is extremely challenging due to the morphological diversity across ontogeny and duration of larval phases. Within Decapoda, developmental stages often differ conspicuously from their adult form, representing a bizarre and mysterious world still left to be discovered. The difficulties with sampling and rearing deep-sea larvae, combined with the lack of taxonomic expertise, argues for the use of molecular methods to aid in identification. Here, we use DNA barcoding combined with morphological methods, to match larval stages with their adult counterpart from the northern Gulf of Mexico and adjacent waters. For DNA barcoding, we targeted the mitochondrial ribosomal large subunit 16S (16S) and the protein coding cytochrome oxidase subunit 1 (COI). These data were combined with previous sequences to generate phylogenetic trees that were used to identify 12 unknown larval and two juvenile species from the infraorder Caridea and the suborder Dendrobranchiata. Once identified, we provide taxonomic descriptions and illustrations alongside the current state of knowledge for all families. For many groups, larval descriptions are missing or non-existent, so this study represents a first step of many to advance deep-sea larval diversity.

Highlights

In order to understand the evolution, distribution and ecology of marine organisms, as well as their impact on community and ecosystem processes, it is important to study their life history and developmental biology [1,2,3]
Our DNA barcoding efforts resulted in a total of 25 de novo 16S sequences and nine de novo cytochrome oxidase subunit 1 (COI) sequences from these larvae
The 14 larval and juvenile species that were successfully matched to their adult counterpart include Alvinocaris stactophila Williams, 1988, Eugonatonotus crassus

Summary

Introduction

In order to understand the evolution, distribution and ecology of marine organisms, as well as their impact on community and ecosystem processes, it is important to study their life history and developmental biology [1,2,3]. Decapod crustaceans, including shrimps, lobsters and crabs and are well-known due to their economic importance in the food, aquarium and pharmaceutical industries [4,5]. Much less is known about their often-complex life histories. The duration of the larval stages varies between and within taxonomic groups, sometimes lasting several months before settling as juveniles or benthic adults [8,9,10,11]. Due to the morphological disparity across ontogeny and duration of larval phases, the identification of planktonic decapod larvae, especially those in the deep sea (>200 m), is extremely challenging

Methods

Results

Discussion

Conclusion