Development of a multilocus-based approach for sponge (phylum Porifera) identification: refinement and limitations

Area of Science:

• Marine Biology
• Molecular Taxonomy
• Genomics

Background:

• Accurate species identification is crucial for understanding marine biodiversity.
• Existing molecular methods for sponge (phylum Porifera) identification lack reliability.
• A standardized molecular protocol is needed to address this identification gap.

Purpose of the Study:

• To develop and validate a multilocus-based Sponge Identification Protocol (SIP) for accurate sponge species identification.
• To evaluate the efficacy of different DNA markers (COI mtDNA, 28S rRNA, ITS) for sponge classification.
• To enhance the reliability of molecular identification by integrating it with morphological analysis.

Main Methods:

• Developed a multilocus-based Sponge Identification Protocol (SIP) using COI mtDNA, 28S rRNA gene (D3-D5), and ITS1-5.8S-ITS2 regions.
• Validated the SIP using a sample of 37 sponge species from 10 orders in South Australia.
• Employed phylogenetic analysis and highest Bit Score for inferring species identity, alongside re-examination of morphological classifications.

Main Results:

• The 28S rRNA gene and COI mtDNA demonstrated superior performance in classifying sponges across various taxonomic levels compared to the ITS region.
• Phylogenetic analysis confirmed the reliability of the developed SIP.
• Integration with morphological identification significantly improved the overall accuracy and effectiveness of the SIP.

Conclusions:

• The multilocus-based Sponge Identification Protocol (SIP) provides a more reliable and effective method for sponge identification.
• Combining molecular data (28S rRNA and COI mtDNA) with accurate morphological identification enhances taxonomic precision.
• Addressing limitations in database diversity and accuracy is essential for broader application of molecular identification protocols.