Size Of Spicules Research Articles

A revision of the trichostrongylid nematode Cooperia Ransom, 1907, from deer game: recent integrative research confirms the existence of the ancient host-specific species Cooperia ventricosa (Rudolphi, 1809).

The trichostrongylid roundworms of the genus Cooperia, which are important in veterinary medicine, currently comprise 19 valid species that parasitize the small intestine of both free-living and domestic ruminants. Only four Cooperia spp. have been reported in Europe, namely C. oncophora, C. punctata, C. curticei and C. pectinata. In 2018-2022, 25 red deer (Cervus elaphus) and 30 sika deer (Cervus nippon) of both sexes and various ages from several remote locations in the Czech Republic were parasitologically examined. Intestinal nematodes of the genus Cooperia were found only in two northern regions. Using the globally recognized key book on trichostrongylid nematodes, they were preliminarily identified as C. pectinata. However, a molecular analysis of cox2 and ITS rDNA gene sequences revealed that Cooperia sp. parasitizing Czech deer is a separate taxon that is more closely related to C. oncophora than to C. pectinata. A subsequent morphological analysis and literature survey confirmed the independence of deer Cooperia sp., which is similar but not identical to bovid C. pectinata. Previous long-term correct identifications of bovid C. pectinata and misidentifications of deer Cooperia species were caused by a fundamental error in the key book mentioned above. Interestingly, the ancient trichostrongylid nematode Strongylus ventricosus from the type host red deer (Cervus elaphus) shot near Greifswald (Germany) was described by Rudolphi in 1809. Rudolphi's type material (one male and four females) was deposited in the Museum für Naturkunde (Berlin). Later, the ancient species S. ventricosus was taken as a synonym for various Cooperia spp. Our current re-examination of the type male indicated that there is a relatively good agreement with our new material from Czech deer regarding the most important characteristics of S. ventricosus (i.e., the shape and size of the male spicules); however, Rudolphi's type material is in rather poor condition. The suggested resurrection of the deer Cooperia sp. in this study as Cooperia ventricosa (Rudolphi, 1809) requires verification by collecting and analyzing new nematode material from the type locality near Greifswald.

ДВА НОВЫХ ДЛЯ НАУКИ ВИДА ОНХОЛАЙМИД (NEMATODA, ENOPLIDA, ONCHOLAIMIDAE) С КОРАЛЛОВЫХ РИФОВ ВО ВЬЕТНАМЕ

Two new for science species of the family Oncholaimidae Dujardin, 1845, found in coral reefs in Vietnam, are described and illustrated. Oncholaimus securus sp. n. is close to O. longispiculosus Gerlach, 1955 according to presence of papilla on tail and spicules length. It differs from it by the longer and thinner body, shorter pharynx and wider labial region. Viscosia graciloides sp. n. in body size and length of spicules is close to V. erasmi Furstenberg, Vincx, 1989, V. macrobursata Keppner, 1987 and V. dossena Leduc, Zhan, 2023. It differs from these species by the form of outer labial sensillae, thinner body, narrower labial region and shorter stoma.

A new species of Aplectana (Nematoda: Cosmocercidae) in Amphisbaena darwinii (Squamata: Amphisbaenidae) from Argentina

In the present study, we describe and illustrate Aplectana nananae n. sp. from the large intestine of Amphisbaena darwinii. Aplectana nananae n. sp. is the second species described in Argentinian amphisbaenian hosts and the 60th species assigned to the genus. This species differs from its congeners by a set of unique characters in males: the presence of 1 unpaired preanal papilla and gubernaculum, the papillae pattern (8+1:2:2) and total number (24+1), very conspicuous and prominent excretory pore, located anterior to the esophageal bulb and the size of spicules (60-70 μm).

Shallow Suberitida (Porifera, Demospongiae) from Peru.

This study describes 81 specimens belonging to Suberitida, collected during the projects Esponjas del Perú (ESPER), Esponjas da América do Sul (EsponjAS) and Semilla UCSUR 2019 (Demospongiae) along the coast of Peru, down to 30 m depth. Using morphological analyses, eight species were identified, one of which is new to science: Halichondria (H.) cristata, H. (H.) prostrata, Hymeniacidon perlevis, Johannesia reticulosa, Plicatellopsis expansa, Suberites aff. latus, Terpios cf. granulosus and Suberites inti sp. nov. Halichondria (H.) cristata, originally from Tierra del Fuego (SW Atlantic), was found widely distributed along the coast of Peru (06° S-14° S). The Magellanican H. (H.) prostrata and the formerly Chilean endemic P. expansa are extended up to Central Peru (12° S). Hymeniacidon perlevis, which presents a highly variable morphology (colour, shape, and spicule size), is firstly reported from the SE Pacific and its continuous occurrence in Peru (04° S-17° S) should be monitored given its supposed invasive potential. Johannesia reticulosa, previously known from Chile (20° S) and southern Peru (13° S), was found further north (11° S). Suberites latus and T. granulosus were originally recorded far-off from the Peruvian coast, in British Columbia and Hawaii, respectively. Thus, the occurrences of Suberites aff. latus and Terpios cf. granulosus are unexpected and should receive special attention in future molecular studies assessing their taxonomical status. Suberites inti sp. nov. characterised by its skeleton with ectosomal bouquets and multispicular choanosomal tracts, and two categories of straight tylostyles, is provisionally endemic to Paracas (13° S). With these results, the number of shallow Suberitida from Peru increases from 2 to 9. However, this number might rise as sampling in deeper environments could bring descriptions of new records.

A new species of Hedruris Nitzsch, 1821 (Nematoda: Hedruridae) parasitic in eel Synbranchus marmoratus Bloch (Synbranchiformes: Synbranchidae) from Argentina, Neotropical Region

During a parasitological survey, specimens belonging to the genus Hedruris (Nematoda: Hedruridae) were found in the stomach of Synbranchus marmoratus Bloch from the Paraná Guazú River, Paraná River basin (Argentina). Comparative morphological studies with its congeners showed that these nematodes belonged to a new species, herein described as Hedruris anguila sp. nov. The new species can be distinguished from remaining Hedruris species by the pseudolabia size, the morphology and size of spicules, the length of female caudal hook, the shape and size of eggs and the particular morphology of the male tail. Hedruris anguila sp. nov. closely resembles Hedruris bifida Rossin & Timi, 2016 and H. suttonae Brugni & Viozzi, 2010, both also described from fish hosts, in the arrangement of caudal papillae and morphology of eggs, but differ in the size of female hook and spicules, and the number of caudal papillae in males. The main morphological features, host range and geographical distribution of all species in the genus Hedruris species are analyzed and discussed. This is the first report of a representative of the family Hedruridae parasitizing a species of Synbranchidae and the eleventh report of the genus Hedruris for a fish host. The number of valid species of Hedruris described was increased to 26, including the new species; 11 for the Neotropical Region and represent the third species found in fish host from Argentina. Based on morphological analysis, the speciation process probably occurred first in Gondwana and the non-mammillated eggs could be an ancestral morphological character. The diet of Synbranchus marmoratus and values of prevalence and mean intensity could indicate that this host species is a true definitive host for this nematode.

Morphologic and genetic characterization ofPterygodermatites(Mesopectines)valladaresin. sp. (Nematoda, Rictulariidae), a parasite of the mouseMus musculus(Rodentia, Muridae) from the Canary Islands (Spain)

A new rictulariid nematode Pterygodermatites (Mesopectines) valladaresi n. sp., parasite of the house mouse Mus musculus (Rodentia: Muridae) in the Canary Islands (Spain) is described by means of light and scanning electron microscopy. The new species belongs to the subgenus Mesopectines characterized by a more or lessdorsal orientation of the buccal capsule, the presence of three oesophageal teeth, the morphology of the oral denticles and the Spirurida type of arrangement of caudal papillae in males. The most discriminant characteristics between the new species and the existing species in the subgenus Mesopectines are (a) the number of cuticular projection pairs (62-64), (b) the size of right and left spicules (respectively, 62-90µm and 123-139µm), (c) the number of midventral fans in males (3-4), (d) the number of prevulvar/total cuticular projection pairs (38-42/63-71), (e) the posterior differentiation of combs into spines in relation to the position of the vulva and (f) the anterior position of the vulva in relation to the oesophagus-intestine junction in females. Parasitized hosts and geographical distribution are also useful criteria to distinguish P. (Me.) valladaresi n. sp. from the remaining species of the subgenus. In addition, the cox1 sequence of the new species is provided and compared with available data of related species.

Insights into the structure and morphogenesis of the giant basal spicule of the glass sponge Monorhaphis chuni

BackgroundA basal spicule of the hexactinellid sponge Monorhaphis chuni may reach up to 3 m in length and 10 mm in diameter, an extreme case of large spicule size. Generally, sponge spicules are of scales from micrometers to centimeters. Due to its large size many researchers have described its structure and properties and have proposed it as a model of hexactinellid spicule development. Thorough examination of new material of this basal spicule has revealed numerous inconsistencies between our observations and earlier descriptions. In this work, we present the results of detailed examinations with transmitted light and epifluorescence microscopy, SEM, solid state NMR analysis, FTIR and X-ray analysis and staining of Monorhaphis chuni basal spicules of different sizes, collected from a number of deep sea locations, to better understand its structure and function.ResultsThree morphologically/structurally different silica layers i.e. plain glassy layer (PG), tuberculate layer (TL) and annular layer (AL), and an axial cylinder (AC) characterize adult spicules. Young, immature spicules display only plain glassy silica layers which dominate the spicule volume. All three layers i.e. PG, TL and AL can substitute for each other along the surface of the spicule, but equally they are superimposed in older parts of the spicules, with AL being the most external and occurring only in the lower part of the spicules and TL being intermediate between AL and PG. The TL, which is composed of several thinner layers, is formed by a progressive folding of its surface but its microstructure is the same as in the PG layer (glassy silica). The AL differs significantly from the PG and TL in being granular and porous in structure. The TL was found to display positive structures (tubercles), not depressions, as earlier suggested. The apparent perforated and non-perforated bands of the AL are an optical artefact. The new layer type that we called the Ripple Mark Layer (RML) was noted, as well as narrow spikes on the AL ridges, both structures not reported earlier. The interface of the TL and AL, where tubercles fit into depressions of the lower surface of the AL, represent tenon and mortise or dovetail joints, making the spicules more stiff/strong and thus less prone to breaking in the lower part. Early stages of the spicule growth are bidirectional, later growth is unidirectional toward the spicule apex. Growth in thickness proceeds by adding new layers. The spicules are composed of well condensed silica, but the outermost AL is characterized by slightly more condensed silica with less water than the rest. Organics permeating the silica are homogeneous and proteinaceous. The external organic net (most probably collagen) enveloping the basal spicule is a structural element that bounds the sponge body together with the spicule, rather than controlling tubercle formation. Growth of various layers may proceed simultaneously in different locations along the spicule and it is sclerosyncytium that controls formation of silica layers. The growth in spicule length is controlled by extension of the top of the axial filament that is not enclosed by silica and is not involved in further silica deposition. No structures that can be related to sclerocytes (as known in Demospongiae) in Monorhaphis were discovered during this study.ConclusionsOur studies resulted in a new insight into the structure and growth of the basal Monorhaphis spicules that contradicts earlier results, and permitted us to propose a new model of this spicule’s formation. Due to its unique structure, associated with its function, the basal spicule of Monorhaphis chuni cannot serve as a general model of growth for all hexactinellid spicules.

A NEW SPECIES OF ALLINTOSHIUS (NEMATODA: HELIGMOSOMOIDEA) FROM TWO SPECIES OF BATS IN BRAZIL.

Allintoshius Chitwood, 1937 is the only genus of the family Ornithostrongylidae (Travassos, 1937) Durette-Desset and Chabaud, 1981 that parasitizes bats. Currently, there are 10 valid species in the genus, of which 3 were described from Brazil. This study describes a new species of Allintoshius and records the first occurrence of a nematode of this genus parasitizing Artibeus lituratus (Olfers). Allintoshius gomesae n. sp. is characterized by having anterior region coiled, cephalic vesicle with cuticular dilation striated transversely, and claviform esophagus. Synlophe in females consists of 16 cuticular ridges at the mid-body. Males have large caudal bursa, and conic and small spicules, and the gubernaculum is absent. Females have uterus didelphic, amphidelphic, tail tip tapered, and ovijector divided into 2 divergent branches, subequal in length. The new species differs from its congeners especially by the shape of the tail tip, vulvar opening, and size of spicules. Allintoshius gomesae is the fourth species of Allintoshius from Brazil and the first report in Ar. lituratus, increasing the number of species recognized of the genus.

Parapharyngodon hispidus n. sp. (Nematoda: Pharyngodonidae) in Tropidurus hispidus (Spix) (Squamata: Tropiduridae) from Caatinga Biome of the Vale do São Francisco, state of Pernambuco, Brazil with a key for the Neotropical species of the genus Parapharyngodon Chatterji.

One species of Parapharyngodon Chatterji (Nematoda: Pharyngodonidae), parasitizing the large intestine of Tropidurus hispidus (Spix) (Squamata: Tropiduridae) in Caatinga biome from Brazil is described and illustrated . This new species differs from a part of its congeners by a set of characters in males: the presence of four pairs of caudal papillae, unpaired post cloacal papilla absent, and smooth anterior cloacal lip. Among the Parapharyngodon species with four pairs caudal papillae, unpaired post clocal papilla absent, and smooth cloacal lips, only P. hispidus n. sp. and P. jairaipurii Rizvi Bursey (Oriental realm), features the same characteristics including sharp pointed tip of spicule, stout terminus or spike of tail of females, and punctate ornamentation of the eggshell. However, these two species are different by the size of spicules (spicules of P. jairaipuri are around 55% of the size spicules of P. hispidus n. sp.); and the arrangement of the caudal papillae (two pairs of adcloacal papillae in P. jaraipuri which are absent in P. hispidus n. sp.). Parapharyngodon hispidus n. sp. is the 55th species assigned to the genus and the 11th species of this genus described in Neotropical hosts.

Two new species of Neofoleyellides (Nematoda: Onchocercidae) parasitising anuran amphibians in South Africa.

The genus Neofoleyellides was recently erected for a single species, Neofoleyellides boerewors from bufonid hosts in South Africa. In present study, we discovered two undescribed species of Neofoleyellides, namely N. steyni n. sp. and N. martini n. sp. parasitising frogs Amietia delalandii and Leptopelis natalensis, respectively. Both species differ from N. boerewors and between each other in shape and relative length of oesophagus, size of spicules, arrangement of genital papillae and morphology of caudal alae in males. Phylogenetic analysis based on concatenated fragments of the 18S ribosomal ribonucleic acid (18S rRNA) and the Cytochrome oxidase c subunit I (COI) genes confirmed both species as Neofoleyellides sister to Icosiellinae and Oswaldofilariinae.

Spiroxys ankarafantsika Roca et Garcia, 2008 (Nematoda: Gnathostomatidae) and Other Nematodes Parasitising Pelusios spp. (Testudines: Pelomedusidae) from South Africa and Mozambique.

The nematode Spiroxys ankarafantsika was described parasitising freshwater turtles Pelusios castanoides and Pelomedusa subrufra from Madagascar. During parasitological surveys at different localities in Mozambique and South Africa the species was recovered from the digestive tract of Pelusios sinuatus, P. subniger and P. castanoides. The species were identified based on the morphology of the anterior extremity (absence of additional teeth on pseudolabia) and the male caudal end (number and arrangement of caudal papillae, size and shape of spicules). Molecular data included a 720bp sequence fragment of 18S rDNA, the entire internal transcribed spacer 1 (ITS1), 5.8S rRNA, and internal transcribed spacer 2 (ITS), flanked by a 288bp 18S rDNA sequence and about 1000bp 28S rDNA sequence, and the mitochondrial cytochrome c oxidase subunit I (cox1) gene marker obtained in the present study. All specimen recovered were identical, based on morphological and molecular data, with the exception of two specimens showing an intraspecific divergence of 9% based on a 694bp sequence fragment of the cox1 gene. Additionally, a Contracaecum sp. third stage larva and an unidentified larva with mushroom-shaped anterior extremity were found. Descriptions of S. ankarafantsika and the two above-mentioned larval stages, supported by photomicrographs and molecular data 18S rDNA, ITS1-5.8S-ITS2-28S and cox1 gene fragments are presented herein.

Two New Species of Free-Living Nematodes (Nematodes, Monhysterida) from the Mouth of the Cấm River, Vietnam

Illustrated descriptions of two new free-living nematodes found in the Cấm River mouth in Vietnam are given. Eumonhystera rivalis sp. n. is morphologically similar to E. dispar (Bastian, 1865); E. sudanensis Zeidan et al., 1989; and E. maxima Gagarin, 1996, but differs by the presence of biocrystal-like bodies, amphid fovea located closer to anterior body end, and longer cephalic setae. Daptonema borealis sp. n. is similar to D. vicinus (Riemann, 1966); D. aquedulcis (Gagarin, 1987); and D. salinae Gagarin, Gusakov, 2014, but has shorter body, shorter cephalic setae, and spicule size.

A new species of Aplectana Railliet Henry (Nematoda: Cosmocercidae) br /in Amphisbaena alba Linnaeus (Squamata: Amphisbaenidae) from Minas Gerais State, Brazil.

In the present study, we described and illustrated Aplectana minaensis n. sp. (Ascaridida: Cosmocercidae) from the intestinal caecum of Amphisbaena alba Linnaeus (Squamata: Amphisbaenidae). Aplectana minaensis n. sp. is the 5th species described in Brazilian hosts and 58th species assigned to the genus. This species differs from its congeners by a set of unique characters in males: the presence of one unpaired precloacal papilla and gubernaculum, the papillae pattern (4+1:2:6) and total number (12+1), and the size of spicules (400-605 µm). Among the Aplectana species with an unpaired precloacal papilla and gubernaculum, only A. minaensis n. sp. and A. nebulosa Gomez, González Sanabria, has less than 20 pairs of caudal papillae. However, these species differ in the number of caudal papillae in males (12+1 vs. 13-14+1, respectively); the number and arrangement of post cloacal papillae (6 pairs: 1st to 4th pairs ventral, 5th pair laterodorsal, 6th pairventral vs. five pairs: 1st and 2nd ventral, 3rd lateral, 4th ventral, 5th lateral); and by the size of spicules (413-600 vs. 85-126 µm).

Two New Species of the Genus Haliclona from Korea.

Two new marine sponges, Haliclona (Reniera) oceanus sp. nov. and Haliclona (Reniera) juckdoensis sp. nov. of the family Chalinidae were collected from Ieodo Ocean Research Station, Ulleung-do Island, Korea by SCUBA in 2016-2017. Morphologically distinct from each other, both species are assigned to the genus Haliclona subgenus Reniera. Haliclona (Reniera) oceanus sp. nov. is similar to H. (H.) ieoensis Kim et al. 2017 in shape, habitat, growth form, but it differs in color, ectosomal, choanosomal skeleton and spicule size. Haliclona (Reniera) juckdoensis sp. nov. is similar to H. (R.) hongdoensis Kang and Sim 2007 in habitat, ectosomal, choansomal skeleton but it differs in spicule size.

Two species of the genus Theristus Bastian, 1865 (Nematoda: Xyalidae) from the hypersaline water bodies of the Crimea (Azov-Black Sea basin).

Morphological descriptions of two species of the genus Theristus Bastian, 1865 belonging to group flevensis, found in the hypersaline water bodies of the Crimean Peninsula, are presented. Theristus siwaschensis sp. n. is morphologically closest to T. flevensis Schuurmans Stekhoven, 1935, T. parambronensis Timm, 1952, T. macroflevensis Gerlach, 1954, T. metaflevensis Gerlach, 1955, but differs from them by the structure of the reproductive system in females, number of cephalic setae and size of spicules. Specimens of T. flevensis found in the Lake Chersonesskoye are similar to the re-description of a large forms of T. flevensis from Chile by Murhy (1966) and Caspian Sea by Chesunov (1981). However, it differs from the Caspian Sea species by having larger amphids, longer cephalic setae and spicules. T. pratti Murph Canaris, 1964 and T. ambronensis Schulz, 1937 are synonymized with T. flevensis.

Two new species of Cosmocercidae (Nematoda: Cosmocercoidea) of Leptodactylus macrosternum Miranda-Ribeiro (Anura: Leptodactylidae) from Caatinga Biome, Brazil.

In the current study, two new species of Cosmocercidae nematodes parasitizing the anuran Leptodactylus macrosternum (Leptodactylidae) from two localities in the municipality of Petrolina, sub-middle São Francisco river, state of Pernambuco, Brazil, were described. Oxysomatium petrolinensis n. sp. differs from all congeneric species for having the male caudal papillae distribution pattern unique in this genus, in which the last three pairs of pre-cloacal papillae are located lateroventrally on the anterior border of the cloacal aperture. Additionally, the new species has an unpaired medial precloacal papilla, seven pairs of postcloacal papillae, and a relatively unique spicule size. Oxyascaris caatingae n. sp. differs from all congeneric species mainly for having males with a medial unpaired precloacal papilla and a distribution pattern of caudal papillae unique to this species, being the only species of the genus with adcloacal papillae. The current study proposes the description of Oxysomatium petrolinensis n. sp., fourth species and the first report of this genus in hosts from the Neotropical region. In addition, it describes Oxyascaris caatingae n. sp., which is the fifth species of the genus.

A novel species Spinonema gracilispiculum sp. n. (Nematoda: Desmodoridae) from the oxygen minimum zone of Eastern Arabian Sea margin.

A new species of marine free living nematode Spinonema gracilispiculum sp. n. is described from the oxygen minimum zone of the eastern Arabian Sea (216m) margin. This new nematode species was found exclusively in the station with sandy texture and dissolved oxygen level 0.35 ml/l and are represented by only few individuals from a single location, despite analysing 288 core samples from an extensive survey along the eastern Arabian Sea OMZ region covering from 06°57'19″N to 21°30'639″N. Spinonema gracilispiculum sp. n. differs from other known species of the genus in the body length, position of the dorsal spine, contour and span of lateral alae, size and shape of spicules, number of pre cloacal setae and sexual dimorphism in presence of dorsal spine and amphideal fovea shape. This is the first record of the genus Spinonema from the Indian Ocean. A pictorial and dichotomous keys to the species of Spinonema are also provided, supplemented with comparative morphometric details of all valid species based on published information.

Revision of Severianoia (Schwenk, 1926) Travassos, 1929 (Nematoda: Oxyuridomorpha) with proposal of S. pachyiuli n. sp. from millipedes of the Western Caucasus

Summary Severianoia pachyiuli n. sp. is described from the hind gut of Pachyiulus krivolutskyi (Diplopoda: Julidae) from the Republic of Adygea, Russian Federation. Females of the new species can be distinguished from those of S. magna by a smaller body and egg size; S. glomericola by smaller eggs and S. dubia by the organisation of the genital tract. Females of S. pachyiuli n. sp. are morphologically close to females of S. severianoi, but in described species males have significantly smaller body and spicule size. Severianoia pachyiuli n. sp. mostly resembles S. glomeridis by the general morphology in both sexes but differs in the position of the vulva, which is in a more posterior position to mid-body level in the described species. The description is supplemented with SEM and/or light microscope images of adults, juveniles and mature eggs. The phylogeny of the species is inferred from 18S and 28S rDNA. The taxonomic position of other representatives of Severianoia is discussed and Cephalobellus tipulae linstowi is regarded as a junior synonym of S. glomeridis.

First deep-sea Hamigera (Demospongiae: Porifera) species associated with Cold-Water Corals (CWC) on antipodal latitudes of the world

Cold-water corals (CWC) are known to be deep-sea biodiversity hotspots, yet there is still a huge knowledge gap regarding their associated fauna. As so, CWC ecosystems pose as a perfect environment for the discovery of new species. In this context two new species of Hamigera (Demospongiae) have been recorded associated with CWC in antipodal parts of the world: Hamigera bibiloniae sp. nov. from the Blanes Canyon (north-western Mediterranean Sea) and Hamigera kellyae sp. nov. from the Clementsville Seamount (Macquire Ridge, New Zealand). Both species represent the first deep-sea records of the previously shallow-water restricted Hamigera, and mostly differ from other species in their huge spicule size, mostly doubling that of shallow-water congeneric species.Furthermore, the current geographical distribution of Hamigera, being only present in the Mediterranean and Pacific areas, might suggest a Tethyan affinity of H. bibiloniae sp. nov. proposing a potential role of deep-sea habitats as climatic refugees.

A new species of Cruzia (Ascaridida; Kathlanidae) parasitizing Salvator merianae (Squamata, Teiidae) from the Atlantic forest in Brazil.

Cruzia lauroi sp. nov. is described from Salvator merianae (Duméril & Bibron, 1839) (Squamata; Teiidae). The new species differs from all previously described species through several morphological characteristics: number of tooth like structures per row in the inner pharynx; and presence of unpaired papillae on the anterior border of the cloacal aperture. However, Cruzia lauroi sp. nov. is closest to C. tentaculata (Rudolphi, 1819), through having similar distribution of male caudal papillae, unpaired pre-cloacal papillae and females with an pre-equatorial vulva. Cruzia lauroi sp. nov. differs from C. tentaculata regarding smaller total body length of individuals, higher number of tooth like structures per row in the pharynx, greater size of diverticulum, smaller size of spicules and a more anterior vulva than in C. tentaculata; and the males do not have caudal alae. Cruzia mazza, C. travassosia, C. mexicana and C. testudines were considered to be species inquirendae, because their descriptions need more detailed taxonomic studies.