Unveiling the Phylogenetic Relationship of Parmarion martensi in Java Through COX1 Gene Analysis

Parmarion martensi Simroth, 1893 is a unique land snail with a highly reduced shell, often referred to as a semi-slug. This species is distributed widely, from Southeast Asia to the Hawaiian Archipelago. In Java, there are two Parmarion species that can only be distinguished by their genital morphology, making identification quite challenging.

Snail Parmarion martensi Simroth, 1893 (source: JMI)

A recent study by Ahmad Ghifari Prasetia, Wawan Hermawan, and Ayu Savitri Nurinsiyah utilized the COX1 gene to reveal the phylogenetic relationships and genetic distances of P. martensi using scientific collections from the Museum Zoologicum Bogoriense. The study employed K2P genetic pairwise distance, as well as phylogenetic analyses using MrBayes and IQ-TREE.

Three Clades Identified

The phylogenetic analysis revealed three distinct clades:

• Clade A – Microparmarion from Borneo (semi-slug outgroup)

• Clade B – P. martensi from Java

• Clade C – P. martensi from Taiwan

Interestingly, the relationship between P. martensi from Java and Taiwan formed a polytomy (unresolved branching), meaning the exact evolutionary relationship remains unclear. A similar pattern was found within Java, where P. martensi from West and East Java formed a polytomy with relatively strong statistical support (PP = 93; BS = 51).

Genetic Distance Findings

The genetic distance analysis showed:

• Within P. martensi from Java: 0 – 4.64%

• Between Java and Taiwan populations: 5.89 – 10.18%

These results suggest that P. martensi has a high COX1 gene variation threshold (0 – 10.18%) while still being considered the same species.

Significance of the Study

This research offers important insights into the genetic diversity of P. martensi across different regions. The high genetic distances between populations raise questions about potential subspecies or local adaptations yet to be identified. For biosystematics, the findings reinforce the importance of integrating morphological and molecular data to better understand biodiversity.

Reference

Prasetia, A. G., W. . Hermawan, and A. S. . Nurinsiyah. “The The Phylogenetic Analysis of Parmarion Martensi Simroth, 1893 Collections Of The Museum Zoologicum Bogoriense From Java Based On Cox1 Gene”. Jurnal Moluska Indonesia, vol. 9, no. 1, Apr. 2025, pp. 25-32, doi:10.54115/jmi.v9i1.120.