Morphological variations caused by fixation techniques may lead to taxonomic confusion in Laeonereis (Polychaeta: Nereididae)

Oliveira, Verônica Maria de; Santos, Cinthya Simone Gomes; Lana, Paulo da Cunha; Camargo, Maurício G.

doi:10.1590/s1984-46702010000100022

Cited by 16 publications

(15 citation statements)

References 14 publications

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“…Lpt/Wp was obtained from illustrations directly (excepting Namalycastis geayi, N. longicirris and N. siolii). This measure was preferred over the number of chaetigers reached when posterodorsal tentacular cirri are placed backwards (Glasby 1999), because differences in preparation of specimens and contraction of body during fixation can cause misleading measurements (Oliveira et al 2010, Bonyadi-Naeini et al 2016.…”

Section: Methodsmentioning

confidence: 99%

The troglomorphic adaptations of Namanereidinae (Annelida, Nereididae) revisited, including a redescription of Namanereis cavernicola (Solís-Weiss & Espinasa, 1991), and a new Caribbean species of Namanereis Chamberlin, 1919

Conde-Vela¹

2017

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Most species belonging to Namanereis Chamberlin, 1919 live in freshwater and subterranean waters, even in water bodies several meters above sea level. A new species belonging to the stygobiont Namanereis group is described here; it shares the common morphological characters of absence of eyes and pigmentation, bifid jaws, elongation of chaetae and cirri, which have been recently regarded as troglomorphies. Because these features are used in evaluations of phylogenetic affinity in Namanereis, a review of these features was made for all known namanereidins, and it was extended to include species in Namalycastis Hartman, 1959. It is shown that elongation of tentacular and dorsal cirri, or elongation of upper sub-acicular falcigers in pre-or post-acicular fascicles, are not exclusive or restricted to species living in subterranean habitats or to Namanereis, because these features are also present in several Namalycastis species. However, the presence of bifid jaws, and the absence of eyes are exclusively found in namanereidins living in subterranean habitats. A hypothetical evolutionary derivation of bifid jaws is proposed, based upon observations of jaw morphology of several species. These exclusive troglomorphic characters (bifid jaws, eyeless) are regarded as convergent features to aphotic environments, and they should be discouraged as indicators of common ancestry. The new species, herein described as Namanereis christopheri sp. n., was collected in a cave 435 m above sea level in Saint Vincent, Caribbean Sea. The species resembles N. cavernicola but it differs because it has shorter tentacular cirri, margin of prostomium entire, rounded neuropodial lobes and broader dorsal cirri throughout body. A key to identify all known Namanereis species is included.

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Section: Methodsmentioning

confidence: 99%

The troglomorphic adaptations of Namanereidinae (Annelida, Nereididae) revisited, including a redescription of Namanereis cavernicola (Solís-Weiss & Espinasa, 1991), and a new Caribbean species of Namanereis Chamberlin, 1919

Conde-Vela¹

2017

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“…Anesthetization facilitates pharyngeal organ eversion (Oliveira et al 2010). Various anesthetics, including Magnesium Chloride (Fauchald 1977; Rouse and Pleijel 2001), Menthol crystals (Coutinho and Santos 2014; Glasby and Hsieh 2006; Russell 1963), MS222 (Tricaine Methane Sulphonate) (Clark 1961; Fauchald 1977), Phenoxyethanol (Hsieh and Li 1998), Ethyl Alcohol (Russell 1963), and various techniques such as cooling the worms (Costa-Paiva et al 2007), have been applied to immobilize and/or relax polychaetes.…”

Section: Introductionmentioning

confidence: 99%

“…Disadvantages include the additional time required for sample preparation (time of relaxation varies with taxa from minutes to hours), and the possibility of distortion of morphological features. For example, inadequate fixation methods or using different anesthetics have resulted in erroneous taxonomical observations of Laeonereis (Oliveira et al 2010) and sabellid polychaetes (Costa-Paiva et al 2007). A suitable anesthetic substance should be safe, environmentally friendly, readily available, easy to use, economically feasible, effective, efficient, and without any morphological modifications resulting from over-relaxation, for example (Costa-Paiva et al 2007, Williams and Van Syoc 2007).…”

Section: Introductionmentioning

confidence: 99%

A new substance to relax polychaete worms (Annelida) prior to morphological study

Rahimian¹,

Glasby²

2016

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A variety of chemical substances have been used to relax and/or immobilize polychaete worms, and other invertebrates, prior to specimen preparation for morphological examination. To solve difficulties encountered during the study of nereidid polychaetes (Annelida: Phyllodocida), an experiment was designed and carried out to investigate a new relaxing agent to immobilize nereidid specimens and stimulate pharynx eversion. The new substance, Dentol® (Khoraman laboratory, Iran), a dental anesthetic and antiseptic medicine containing 10% Carvacrol as the effective ingredient, was used for the first time and compared with other substances that have been used traditionally in polychaete studies. Crosstab analysis showed significant differences between different treatment groups, with Dentol® providing much better results for all considered criteria.

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“…Likewise, L. brunnea was recently reinstated, and its distribution restricted to Pacific estuaries along Central America (Dean, 2001). A contrary perspective, based upon some morphological distortions due to preservation, led Oliveira, Santos, Lana and Camargo (2010) conclude that L. acuta is a junior synonym of L. culveri, but gave no details about a direct comparison of parapodial features.…”

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confidence: 99%

Morphological distinction between estuarine polychaetes: Laeonereis culveri and L. nota (Phyllodocida: Nereididae)

Jesus-Flores¹,

Salazar-González²,

Salazar‐Vallejo

2016

RBT

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Abstract:The family Nereididae includes more than 500 polychaete species described worldwide, and includes species common in many benthic environments, but some other species may tolerate freshwater or can even thrive in humid substrates in tropical forests. In estuarine environments, nereidid polychaetes can be abundant and relevant as a food source for resident or migratory birds. Laeonereis culveri (Webster, 1879) is a common estuarine species found in tropical and subtropical Atlantic American shores and was described from New Jersey; its median and posterior parapodia have upper notopodial ligules usually longer than the lower ones, and the latter are parallel to the notaciculae throughout the body. L. culveri distribution is from Connecticut to central Argentina; however, this wide distribution might be due to the inclusion of several other species as junior synonyms, despite that some morphological differences were found between them. One of such species is L. nota (Treadwell, 1941), that was described from Texas; its parapodia have notopodial ligules of about the same size, and the lower ones are oblique to the notaciculae. In order to clarify the differences between these two species, and to define which inhabits the Northwestern Caribbean region, topotype materials from these two species and specimens from Chetumal Bay were collected, and their morphological features were compared. Our results indicated that L. culveri and L. nota are different species and that the latter is found in Chetumal Bay. On the basis of mature specimens, L. culveri is hereby restricted to the Northern Gulf of Mexico and Northwestern Atlantic Ocean, and L. nota is reinstated and its distribution extends from Texas, in the Gulf of Mexico to Chetumal Bay, in the Northwestern Caribbean Sea. A key to identify all species in Laeonereis Hartman (1945) is also included. Rev. Biol. Trop. 64 (1): 189-201. Epub 2016 March 01.Key words: taxonomy, Polychaeta, parapodial variations, Gulf of Mexico, Caribbean Sea, Annelida, shorebirds.The polychaete family Nereididae de Blainville, 1818 includes species common in many benthic environments and has over 700 species in 45 genera worldwide (Read, 2015;Santos, Pleijel, Lana, & Rouse, 2005) Because they have been known since Linneaus and are frequently included in invertebrate zoology texts, this family is probably one of the best known among the polychaetes. Some nereidid species occur in estuarine or freshwater environments (Glasby & Timm, 2008), usually having more species than any other polychaete family in freshwater reservoirs (Foster, 1972); some species can even thrive in humid substrates in tropical forest trees (Glasby, Kitching, & Ryan, 1990;Glasby, Mogi, & Takahashi, 2003).The morphological diagnostic features are well known for distinguishing genera among nereidids including prostomial, parapodial, chaetal and pharynx features, despite the fact that many undergo an impressive transformation of the body for reproduction (eyes become larger, and parapodia are transformed by a widening ...

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Morphological variations caused by fixation techniques may lead to taxonomic confusion in Laeonereis (Polychaeta: Nereididae)

Cited by 16 publications

References 14 publications

The troglomorphic adaptations of Namanereidinae (Annelida, Nereididae) revisited, including a redescription of Namanereis cavernicola (Solís-Weiss & Espinasa, 1991), and a new Caribbean species of Namanereis Chamberlin, 1919

The troglomorphic adaptations of Namanereidinae (Annelida, Nereididae) revisited, including a redescription of Namanereis cavernicola (Solís-Weiss & Espinasa, 1991), and a new Caribbean species of Namanereis Chamberlin, 1919

A new substance to relax polychaete worms (Annelida) prior to morphological study

Morphological distinction between estuarine polychaetes: Laeonereis culveri and L. nota (Phyllodocida: Nereididae)

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Morphological variations caused by fixation techniques may lead to taxonomic confusion in Laeonereis (Polychaeta: Nereididae)

Cited by 16 publications

References 14 publications

The troglomorphic adaptations of Namanereidinae (Annelida, Nereididae) revisited, including a redescription of Namanereis cavernicola (Solís-Weiss &amp; Espinasa, 1991), and a new Caribbean species of Namanereis Chamberlin, 1919

The troglomorphic adaptations of Namanereidinae (Annelida, Nereididae) revisited, including a redescription of Namanereis cavernicola (Solís-Weiss &amp; Espinasa, 1991), and a new Caribbean species of Namanereis Chamberlin, 1919

A new substance to relax polychaete worms (Annelida) prior to morphological study

Morphological distinction between estuarine polychaetes: Laeonereis culveri and L. nota (Phyllodocida: Nereididae)

Contact Info

Product

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The troglomorphic adaptations of Namanereidinae (Annelida, Nereididae) revisited, including a redescription of Namanereis cavernicola (Solís-Weiss & Espinasa, 1991), and a new Caribbean species of Namanereis Chamberlin, 1919

The troglomorphic adaptations of Namanereidinae (Annelida, Nereididae) revisited, including a redescription of Namanereis cavernicola (Solís-Weiss & Espinasa, 1991), and a new Caribbean species of Namanereis Chamberlin, 1919