Abstract
During a visit to polychaete–rearing facilities in the vicinity of Bay of Cádiz (SW Iberian Peninsula, Atlantic Ocean), we sampled two populations of Marphysa (Annelida, Eunicidae) originally occurring at nearby intertidal soft bottoms, one being more than twice as long as the other at the same age. We analysed them using partial sequences of two mitochondrial genes, 16S rDNA and Cytochrome Oxidase I, and classical morphological observations. Our molecular results confirmed that the two populations corresponded to two different species, with PTP species delimitation values ranging from 0.973 (long–bodied species) to 0.999 (short–bodied species). Morphologically, the short–bodied species resembles the recently redescribed M. sanguinea (Montagu, 1813), but differs mainly in having some parapodia with two subacicular hooks (one bidentate and one unidentate) and three types of pectinate chaetae, Two isodont present all along the body, and one particularly large anodont asymmetric appearing only from mid–posterior parapodia. The long–bodied species resembles Marphysa aegypti Elgetany, El-Ghobashy, Ghoneim and Struck, 2018 both in size and in having very robust, unidentate subacicular hooks (single in most parapodia, two–both similar in size and form–in some posterior parapodia), but differs, among other features, in the maxillary formula, the number of acicula per parapodia and the number and shape of pectinate chaetae. Accordingly, we are here fully illustrating and formally describing the two Iberian populations as Marphysa gaditana sp. nov. (short–bodied) and Marphysa chirigota sp. nov. (long–bodied) and we are emending the description of M. aegypti based on our revision of the type material. Also, we discuss on the distribution of the species of the sanguinea–group and on the relevancy of taxonomically robust studies when dealing with species of commercial interest having the potential of being globally spread through human activities, as well as on the misunderstandings caused by the incorrect use of the “cosmopolitan species” concept.
Highlights
In addition to the intrinsic interest of the annelid polychaetes as ubiquitous and highly abundant members of virtually all marine benthic ecosystems, some of them are increasingly exploited commercially
For Cytochrome Oxidase I (COI) sequences, the lowest K2P pairwise distances for M. gaditana sp. nov. were 0–1.9% with specimens from France, Portugal and East Coast of USA misidentified as M. sanguinea (Fig 2, green clade), while for Marphysa chirigota sp. nov., the lowest COI K2P pairwise distances were with M. aegypti (2.9–3.74%)
Marphysa chirigota sp. nov. resulted in a species distinct from all others of the genus that have 16S and COI sequences available in GenBank, while M. gaditana sp. nov. formed the a single clade together with numerous specimens previously identified as Marphysa sanguinea and Marphysa sp. (Fig 2)
Summary
In addition to the intrinsic interest of the annelid polychaetes as ubiquitous and highly abundant members of virtually all marine benthic ecosystems, some of them are increasingly exploited commercially. Importing allochthonous species is a well–established alternative to exploiting local populations This transfers the harvesting impact to the often remote areas where baits are collected. This may lead to accidental introductions (even to invasions) whether some viable specimens manage to escape from fishing hooks or are directly released into the wild by anglers at the end of their fishing journey [12, 13]. A more environmentally friendly alternative is rearing autochthonous species, the number of feasible initiatives is still very low (e.g., [4, 14]) These activities may entail the destruction of local habitats either when implementing the facilities or during the routine functioning activities. On the other hand, culturing allochthonous species must be disregarded and discouraged due to the implicit risks of accidental releasing of living specimens that would directly impact the wild surroundings
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
