Genetic differences between two sibling species of the Polydora ciliata complex (Polychaeta: Spionidae)

Karl

2007

Invertebrate Biology

Abstract. We have collected evidence that the nominal species, Polydora cornuta Bosc 1802, contains at least three separate species in North America. Specimens of P. cornuta were collected in California, Florida, and Maine, raised in the laboratory, and assessed for reproductive compatibility, genetic similarity, gamete characteristics, and developmental rates. Reproductive crosses between each combination of sex and population revealed variable levels of hybridization at the level of fertilization. Percent fertilization was very low for all combinations (0–7%) except for California females crossed with Florida males (42%). In all interpopulation crosses, fertilized eggs arrested in cleavage and no viable larvae were produced. All pairwise comparisons of the studied populations showed significant differences in multiple reproductive traits. Mitochondrial cytochrome oxidase subunit I DNA sequences revealed large differences between Florida and California worms with a maximum likelihood genetic distance of d=0.860, while Florida and Maine worms were d=0.806, and California and Maine d=0.156. California and New Zealand worms were very similar genetically (d=0.010). These data strongly suggest that populations of P. cornuta in North America comprise a cryptic species complex composed of at least three distinct lineages.

Section: Discussionmentioning

confidence: 62%

The Polydora cornuta complex (Annelida: Polychaeta) contains populations that are reproductively isolated and genetically distinct

Karl

2007

Invertebrate Biology

“…; Kruse & Reise ; Kruse et al . ; Sato & Nakashima ; Lewis & Karageorgopoulos ; Paxton & Åkesson ), life history characteristics (Grassle & Grassle ; Rice & Simon ; Wilson ; Mustaquim ; Westheide & Rieger ; Manchenko & Radashevsky , ; Bonse et al . ; Bastrop et al .…”

Section: Why Are Cryptic Species Important?unclassified

Cryptic polychaete diversity: a review

2013

Nygren, A. (2014). Cryptic polychaete diversity: a review. -Zoologica Scripta, 43, 172-183. This review summarises the current knowledge on cryptic species of polychaetes, one of the most dominant taxa in marine communities, and gives a brief overview of the different methods that has been used for their disclosure. Cryptic species constitute an important part of biodiversity and they are common among all kinds of polychaetes, with different life history traits, and may have sympatric as well as allopatric distributions. It is emphasised that cryptic species must not be neglected for a variety of reasons, and even though the magnitude of cryptic species is largely unknown the available data on polychaetes clearly demonstrate that morphology alone seriously underestimate the number of species. It is suggested that future research should focus on appropriately designed case-studies using combined approaches, as well as on large-scale whole sample analyses using next-generation sequencing in order to be able to answer the many questions that still remains.

“…Mor phological, biological and ecological approaches are mainly used to identify polydorid species, along with differences in methyl green staining (Read 2010) and information from allozyme analyses (Manchenko & Radashevsky 1993, 2002, Mustaquim 1988, Radashevsky & Pankova 2006. A molecular biological approach has been suggested in order to distinguish the species with closely similar morphology, but there have been few such studies in the Spionidae, particularly in polydorids (Bastrop et al 1998, Rice et al 2008.…”

Section: Introductionmentioning

confidence: 99%

Morphology, 18S rRNA gene sequence and life history of a new Polydora species (Polychaeta: Spionidae) from northeastern Japan

Teramoto¹,

Sato-Okoshi²,

Abe³

et al. 2013

Aquat. Biol.

A new species of spionid polychaete, Polydora onagawaensis, is described from mollusk shells in Pacific waters of northeastern Japan. Its nuclear 18S rRNA gene sequence as well as its morphology, reproductive features, life history and infestation characteristics are reported. Polydora onagawaensis sp. nov. belongs to the Polydora ciliata/websteri group and has a moderate size and variable black pigmentation on the palps and body. Up to 115 worms were found boring in a single scallop shell from suspended cultures in Onagawa Bay, with significantly higher numbers in the right than in the left valve. Females repeatedly deposited a string of egg capsules from around October to June (seawater temperature was below 15°C). The larvae developed inside the egg capsules for 2 wk (10°C, laboratory conditions), until the 3-chaetiger stage, before being released as planktonic larvae. The main spawning occurred in December, recruitment onto the shells increased after January, and most large worms disappeared between July and October. Thus, the estimated life span is around 1.5 yr after settlement. Details on biology and gene information not only contribute to distinguishing the species from other polydorids similar in morphology, but also allow control of polydorid infestation in mollusk aquaculture.