Prosorhochmus belizeanus sp. nov. (A–C) A series of transverse sections through the frontal organ from anterior to posterior; lateral acidophilic regions marked by arrowheads. (D) Transverse section through the cerebral organ furrow and posterior ocellus. (E) Transverse section through the cerebral organ (outlined). (F) Transverse section through the intestinal region of a mature male. (G, H) Slightly oblique transverse sections through the tip of the head: prosorhochmid smile (G) and frontal organ (H). Scales on (A–E) -50 mm; on (G, H) -100 mm; on (F) -200 mm. Abbreviations: agl -acidophilic cephalic glands, bgl basophilic cephalic glands, co -cerebral organ, cof -cerebral organ furrow, fo -frontal organ, int -intestine, pb -proboscis, pc -pigment cup of ocellus, rhd -rhynchodeum, ts -testis.

Source publication

Revision of the smiling worms, genus Prosorhochmus Keferstein, 1862, and description of a new species, Prosorhochmus belizeanus sp. nov. (Prosorhochmidae, Hoplonemertea, Nemertea) from Florida and Belize

Article

Full-text available

May 2008

A new species of Prosorhochmus is described from Belize and Florida based on morphological, reproductive and sequence data. Similar to Prosorhochmus nelsoni (Sanchez, 197354. Sanchez , M. 1973. Sobre 4 especies de nemertinos de Quintero (Chile) [On the four nemertean species from Quintero (Chile)].. Studies on Neoropical Fauna, 8: 195–214. [Taylor...

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... posterior portion of the cerebral organs slightly overlaps with the anterior portion of the brain. Each organ opens at the level of the anterior pair of eyes into a reduced ventro-lateral cerebral organ furrow, which is nothing more than a shallow ventro-lateral crescent- shaped groove ( Figures 1C, 2B) lined with a strongly acidophilic epithelium ( Figures 5D-E). The cerebral organ canals are not branched. ...

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... cerebral organ canals are not branched. The posterior portion of the cerebral organ is a glandular lobe with finely granular acidophilic secretion ( Figure 5E). ...

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... collected by SAM from the Adriatic coast of Croatia were slightly longer than Prosorhochmus chafarinensis from Chafarinas Islands but otherwise conformed to the species description. Stylet characteristics, measured on six specimens from Croatia were not statistically significant from the originally described for P. chafarinensis by Frutos et al. (1998) (p50.05). We pooled the measurements and adjusted the ranges and means accordingly in the species diagnosis. ...

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Collection sites of the specimens examined in the present study.

Holotype specimens of new Tetrastemma species; photographs were taken...

A maximum-likelihood (ML) tree based on concatenated sequences of two...

Three new species in Tetrastemma Ehrenberg, 1828 (Nemertea, Monostilifera) from sublittoral to upper bathyal zones of the northwestern Pacific

Article

Full-text available

Feb 2023

Monostiliferous nemerteans in the genus Tetrastemma Ehrenberg, 1828 are generally characterized as having four eyes, and they occur worldwide, from the intertidal zone to the deep-sea bottom. Recent extensive sampling of Tetrastemma has explored the high species diversity, including many undescribed forms, but phylogenic analysis has revealed non-m...

Anterior regeneration in Baseodiscus hemprichii (Nemertea: Heteronemertea)

Article

Apr 2019

DNA Taxonomy of Paranemertes (Nemertea: Hoplonemertea) with Spirally Fluted Stylets

Article

Dec 2015

Of the 14 nominal species that are now or have ever been assigned to the genus Paranemertes Coe, 1901 , four have been reported to have stylets with a spirally fluted or braided appearance. Although differentiation in color patterns has been documented among species/populations, these nemerteans share similar external characters. Using the sequence...

Identification of Differentially Expressed Proteins During Regeneration of Dendrorhynchus zhejiangensis Using the Comparative Proteomic Analysis

Article

Full-text available

Nov 2015

In order to examine underlying mechanisms of the impressive regeneration in Dendrorhynchus Zhejiangensis, a two-dimensional gel electrophoresis (2-DE) combined with mass spectrometric analysis was employed. 70 proteins involved in regenerative process were identified and 33 proteins were up-regulated and others were down-regulated in fracture injur...

Cladistic Analysis of the Eureptantic Nemerteans (Nemertea : Hoplonemertea)

Article

Full-text available

Jun 1995

A phylogeny for the 34 species we consider well enough described in the suborder Eureptantia (phylum Nemertea) is inferred by cladistic analysis based on 38 morphological characters. The phylogenetic reconstruction indicates that many previously recognised genera and families are paraphyletic. These findings are discussed and compared with earlier...

Brazilian Northeast coast Prosorhochmus belizeanus (Hoplonemertea: Nemertea) populations analyses reveal colonization by founder effect

Article

Jun 2024

Prosorhochmidae, known as smiling worms, are hoplonemerteans of great interest to nemertologists, since some species display viviparity and hermaphroditism, both rare traits in this phylum, and can be found in terrestrial and marine environments. Prosorhochmus is a predominantly marine genus and was never recorded on the Brazilian coast. The present study documents the first record of the oviparous Prosorhochmus belizeanus, along with population genetic diversity analyses. Here, we sequenced cytochrome c oxidase subunit 1 (COI) and 16S ribosomal RNA (16SrRNA) regions from individuals of three localities along the Brazilian Northeast coast. From these analyses, we found moderate genetic diversity, no genetic structuring, and no clear geographical pattern. In addition, migration analysis evidenced some influence of the Brazilian Current in the species’ dispersion. Those findings indicate colonization by a small number of mtDNA lineages followed by population stability and shed light into the importance of deepening the knowledge about those organisms to elucidate genetic and dispersion patterns of oviparous invertebrates of rocky shores.

Genome Size Dynamics in Marine Ribbon Worms (Nemertea, Spiralia)

Article

Full-text available

Aug 2021

Nemertea is a phylum consisting of 1300 mostly marine species. Nemertea is distinguished by an eversible muscular proboscis, and most of the species are venomous. Genomic resources for this phylum are scarce despite their value in understanding biodiversity. Here, we present genome size estimates of Nemertea based on flow cytometry and their relationship to different morphological and developmental traits. Ancestral genome size estimations were done across the nemertean phylogeny. The results increase the available genome size estimates for Nemertea three-fold. Our analyses show that Nemertea has a narrow genome size range (0.43–3.89 pg) compared to other phyla in Lophotrochozoa. A relationship between genome size and evolutionary rate, developmental modes, and habitat was found. Trait analyses show that the highest evolutionary rate of genome size is found in upper intertidal, viviparous species with direct development. Despite previous findings, body size in nemerteans was not correlated with genome size. A relatively small genome (1.18 pg) is assumed for the most recent common ancestor of all extant nemerteans. The results provide an important basis for future studies in nemertean genomics, which will be instrumental to understanding the evolution of this enigmatic and often neglected phylum.

Higher classification of the Monostilifera (Nemertea: Hoplonemertea)

Article

Full-text available

Jan 2021
ZOOTAXA

Hiroshi Kajihara

The nemertean order Monostilifera consists of 594 species in 127 genera and is distributed worldwide. Within the Monostilifera, two suborders have been recognized, Cratenemertea and Eumonostilifera. Within the latter, two, unranked clade names, Oerstediina and Amphiporina, were recently proposed without formal taxonomic definition. In this article, I give morphological circumscriptions and clade definitions for Cratenemertea, Eumonostilifera, Oerstediina, Plectonemertidae, Oerstediidae, and Amphiporina. Oerstediina and Amphiporina are placed on the Linnaean rank of infraorder. Constituent genera and species for each higher taxon are tabulated. The genus Amphiporella Friedrich, 1939 is herein replaced with Germanemertes nom. nov. to avoid homonymy with the Carboniferous fossil bryozoan genus Amphiporella Girty, 1910. Loxorrhochmidae Diesing, 1862 is declared a nomen oblitum relative to Tetrastemmatidae Hubrecht, 1897, a nomen protectum under Article 23.9 of the International Code of Zoological Nomenclature. There remain 308 species of eumonostiliferans whose infraorder affiliation is uncertain due to the lack of information on vascular morphology and molecular sequence data. The suborder affiliation of the two species Cinclidonemertes mooreae Crandall, 2010 and Verrillianemertes schultzei Senz, 2001 is left uncertain.

Three Species of Ribbon Worms (Nemertea) from Cebu, the Philippines

Article

Full-text available

Oct 2020

Hiroshi Kajihara

Three species of nemerteans, Balionemertes cf. australiensis Sundberg, Gibson, and Olsson, 2003 (Palaeonemertea), Prosadenoporus olympiae sp. nov. (Hoplonemertea: Eumonostilifera), and Coella gloriae sp. nov. (Hoplonemertea: Polystilifera: Reptantia), are reported based on material collected intertidally at a rocky shore in Cebu Island, Republic of the Philippines. Cytochrome c oxidase subunit I (COI) barcode sequences of these species have earlier been published elsewhere. The Cebu specimen that is herein identified tentatively as Balionemertes cf. australiensis posseses i) small black dots on the ventral body surface, ii) a neurochord in the lateral nerve, iii) serial rhynchocoelic septa, and iv) nephrostomes, characters that were not mentioned in the original description of the species from Australia; the exact species identification requires barcode sequences from topotypes. Prosadenoporus olympiae can be differentiated morphologically from other congeners by having three accessory-stylet pouches; when alive, worms of this species showed negative hydrotaxis. Coella gloriae differs from all the reptantic polystiliferans by having i) four rows of the eyes, ii) the cephalic furrows, iii) no dorsal marking, iv) separate mouth and proboscis openings, v) blind-ending extracerebral vessels, vi) non-forked fibre core in the dorsal ganglia, vii) the subdorsal nerves, and viii) the cerebral organs partly overlapping the brain.

Resolving a 200-year-old taxonomic conundrum: neotype designation for Cephalothrix linearis (Nemertea: Palaeonemertea) based on a topotype from Bergen, Norway

Article

Full-text available

Jun 2019

Hiroshi Kajihara

The taxonomic identity of the palaeonemertean Cephalothrix linearis (Rathke, 1799) has been obscure for nearly two centuries, because its original description applies to almost any congeners, including Cephalothrix filiformis (Johnston 1828) and Cephalothrix rufifrons (Johnston, 1837), which occur commonly in the North Sea and adjacent waters. In this paper, I redescribe C. linearis based on two topotypes from Bergen, one herein designated as the neotype for C. linearis, because Rathke’s original material is not extant; I invoke Article 70.3.2 of the International Code of Zoological Nomenclature to fix Planaria linearis Rathke, 1799 as the type species of Cephalothrix Örsted, 1843 for the sake of stability. From the neotype, I determined sequences of the 28S rRNA, 16S rRNA, and cytochrome c oxidase subunit I (COI) genes. Using the COI sequence, I inferred the phylogenetic position of C. linearis along with 316 cephalotrichid sequences currently available in public databases. A tree-based species delimitation analysis detected 43 entities among them, with 34 in Cephalothrix and nine in eitherBalionemertes or Cephalotrichella. I apply valid species names to 12 of the 34 entities in Cephalothrix. I tabulated a total of 36 nominal species that are likely the members of the genus; the following five were excluded even though their specific names were originally combined with Cephalothrix: Cephalothrix armata Ulyanin, 1870 [Monostilifera, possibly Emplectonema gracile (Johnston, 1837)], Cephalothrix fragilis Bürger, 1892 [now Cephalotrichella signata (Hubrecht, 1879)], Cephalothrix signata Hubrecht, 1879 [now in Cephalotrichella], Cephalothrix unipunctata Parfitt, 1867 [now Tetrastemma melanocephalum (Johnston, 1837) (Monostilifera)], and Cephalothrix viridis Chapuis, 1886 [possibly Heteronemertea]. The five names cephalothrix Diesing, 1850 (as Borlasia cephalothrix), kroyeri Diesing, 1850 (as Cephalothrix kroyeri), linearis Diesing, 1850 (as Borlasia linearis), lineata Claparède, 1862 (as Cephalothrix lineata), and oerstedii Diesing, 1850 (as Cephalothrix oerstedii) aredeclared nomenclaturally unavailable.

Microsatellites of the self-compatible nemertean Prosorhochmus americanus (Hoplonemertea)

Article

Full-text available

Nov 2014

Thousands of microsatellite loci were identified in the nemertean Prosorhochmus americanus through enrichment-isolation and next-generation sequencing protocols. We tested 48 loci for amplification and subsequently genotyped 17 loci in 30 individuals from three North American populations. Most loci were polymorphic within and across populations; six were monomorphic. The number of alleles per locus ranged from 1 to 9 (mean 4.35, SD 2.37). Cross-species amplification in four nemertean species revealed extended marker utility. These loci will enable investigations of colonization potential and natural history in this selfing, putatively introduced species.

A shore-based preliminary survey of marine ribbon worms (Nemertea) from the Caribbean coast of Colombia

Article

Full-text available

Sep 2014

A checklist of benthic ribbon worm species from the Caribbean coast of Colombia is presented, including synonyms, distributions, a photographic record, and the main morphologic characters of each species for a rapid identification. This is the first research focused broadly on nemerteans in Colombia. 54 specimens of nemerteans were hand-collected from the rocky littoral of two different localities, and identified according to personal experience and specialist literature. 13 species were found; of which 11 represent new records for the country. These species belong to eight different traditionally used families: Tubulanidae, Valenciniidae, Lineidae, Amphiporidae, Cratenemertidae, Emplectonematidae, Drepanophoridae and Ototyphlonemertidae. The most common and abundant species was Dushia atra. The biodiversity of nemerteans in Colombia seems to overlap with the nemertean fauna from Florida and Brazil, explained by the convergence of the North Brazil Current, Guiana Current, Caribbean Currents and the Panama-Colombia Contracurrent in the sampled region. The results of this work suggest that the Caribbean coast of Colombia is a region with a high diversity of nemerteans, and provide important taxonomic data for environmental assessments and future biological research.

A DNA-based description of a new nemertean (phylum Nemertea) species

Article

Full-text available

Jan 2011
MAR BIOL RES

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The Invention of the Pilidium Larva in an Otherwise Perfectly Good Spiralian Phylum Nemertea

Article

Full-text available

Nov 2010
INTEGR COMP BIOL

Svetlana A Maslakova

One of the most remarkable larval types among spiralians, and invertebrates in general, is the planktotrophic pilidium. The pilidium is found in a single clade of nemerteans, called the Pilidiophora, and appears to be an innovation of this group. All other nemerteans have either planktotrophic or lecithotrophic juvenile-like planuliform larvae or have direct development. The invention of the pilidium larva is associated with the formation of an extensive blastocoel that supports the delicate larval frame and elaborate ciliary band. Perhaps the most striking characteristic of the pilidium is the way the juvenile worm develops inside the larva from a series of isolated rudiments, called the imaginal discs. The paired cephalic discs, cerebral organ discs, and trunk discs originate as invaginations of larval epidermis and subsequently grow and fuse around the larval gut to form the juvenile. The fully formed juvenile ruptures the larval body and, more often than not, devours the larva during catastrophic metamorphosis. This review is an attempt to examine the pilidium in the context of recent data on development of non-pilidiophoran nemerteans, and speculate about the evolution of pilidial larval development. The author emphasizes the difference between the planuliform larvae of Palaeonemerteans and Hoplonemerteans, and suggest a new name for the hoplonemertean larvae--the decidula.

Feeding rates of the nemertean Prosorhochmus americanus (Hoplonemertea) on two species of gammaridean amphipods

Article

Sep 2010
INVERTEBR BIOL

The intertidal hoplonemertean Prosorhochmus americanus is a common inhabitant of the fouling community of rock jetties of the southeast coast of the United States. We undertook a laboratory investigation of the feeding rate of this nemertean, which is a suctorial predator of amphipod crustaceans that co-occur in abundance in the fouling community. While submerged in water (simulating high tide), worms fed on the tube-building amphipods Jassa falcata and Corophium cf. insidiosum at rates of 0.19 amphipods nemertean−1 d−1 (n=10) and 0.26 amphipods nemertean−1 d−1 (n=14), respectively. These predation rates were not significantly different (two-tailed t-test, p>0.05), and are similar to those estimated in laboratory studies of other suctorial nemerteans. Many nemerteans are typically more active at night, and indeed, adults of P. americanus consumed more individuals of J. falcata during dark periods than during light periods (χ2 analysis, p<0.05). However, no difference in consumption of individuals of C. cf. insidiosum was observed in dark versus light. We attribute these contrasting results to differences in tube-building behavior exhibited by these two species of amphipod under laboratory conditions. Our results and those of other laboratory investigations suggest that nemerteans that prey on amphipods feed at a rate of ∼0.2 prey items nemertean−1 d−1, but under natural conditions this rate may not be obtained because of limited feeding time, longer foraging distances, and emigration of prey from regions of high nemertean activity.

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