A morphological guide of neotropical freshwater sponge spicules for paleolimnological studies

Freshwater sponges (Porifera: Spongillida) are sessile invertebrates with skeletons composed of siliceous elements termed spicules. Sponge spicules (megascleres, microscleres, and gemmuloscleres) are characterized by widely varying sizes and shapes. These spicules are well-preserved in lacustrine, wetland, and riverine sediments and hold significant ecological and limnological information that can be applied as diagnostic tools in reconstructions of Quaternary environments. However, problems with taxonomy and the absence of systematic guidelines and standards of identification represent major challenges to utilizing freshwater sponges as a paleo-proxy. Here, we present a well-illustrated extraction protocol and morphological guide to the Neotropical freshwater sponge fauna. This guide is intended to introduce researchers and students to the study of freshwater sponges and their use as a diagnostic tool in paleoecology and paleolimnology

Corvoheteromeyenia Ezcurra de Drago, 1979 (Spongillidae, Porifera): Genus review with proposal of neotype of Corvoheteromeyenia heterosclera (Ezcurra de Drago, 1974)

Calheira, Ludimila, Pinheiro, Ulisses (2016): Corvoheteromeyenia Ezcurra de Drago, 1979 (Spongillidae, Porifera): Genus review with proposal of neotype of Corvoheteromeyenia heterosclera (Ezcurra de Drago, 1974). Zootaxa 4126 (3): 351-374, DOI: 10.11646/zootaxa.4126.3.

Anheteromeyenia Schroder 1927

Key to species of Anheteromeyenia Schröder, 1927 1. Megascleres in a single category.......................................................................... 2 - Megascleres in two categories...................................................................... A. vitrea 2. Gemmuloscleres pseudobirotules......................................................................... 3 - Gemmuloscleres acanthoxeas and acanthostrongyles......................................... A. diamantina sp. nov. 3. Megascleres acanthoxeas gradually pointed..................................................... A. cheguevarai - Megascleres acanthoxeas abruptly pointed........................................................... A. ornataPublished as part of Calheira, Ludimila & Pinheiro, Ulisses, 2018, A new species of Anheteromeyenia (Porifera, Demospongiae) with an emended diagnosis of the genus, pp. 129-136 in Zootaxa 4378 (1) on page 134, DOI: 10.11646/zootaxa.4378.1.9, http://zenodo.org/record/116813

Anheteromeyenia diamantina Calheira & Pinheiro 2018, sp. nov.

<i>Anheteromeyenia diamantina</i> sp. nov. <p> <b>Type locality.</b> Poço Halley, Lençóis, Chapada Diamantina, Bahia State, Brazil.</p> <p> <b>Material Studied. Holotype.</b> UFPEPOR 2061, Poço Halley, Lençóis, Bahia, Brazil, (12°33’47.9”S 41°23’46.3”W), coll. Calheira, L. 31.xii.2015. <b>Paratypes</b>. UFPEPOR 2062, coll. L. Calheira, 31.xii.2015; UFPEPOR 2063, 2064, 2065, coll. F. Andrade, 31.xii.2015 (collected together with the holotype).</p> <p> <b>Diagnosis</b>. One category of megascleres (exclusively smooth oxeas); microscleres absent; acanthoxea and acanthostrongyle gemmuloscleres radially embedded in the gemmular theca, emerging more or less from the inner layer according to their different levels of insertion.</p> <p> <b>Description of holotype.</b> UFPEPOR 2061 encrusting, less than 10 mm thick. Hispid surface. Oscules inconspicuous. Colour in life green turning creamy white after preservation in ethanol 70%. Consistency soft, compressible and fragile. <b>Spicules.</b> Megascleres oxeas (267–335.1–406 / 10–13.1–16 µm), microscleres absent, gemmuloscleres acanthoxeas (161–172.3–180 / 6–7–10 µm) and acanthostrongyles (100–146–177 / 6–7–10 µm). Gemmules scattered throughout the sponge (567–689.9–867 µm in diameter) (Table 1).</p> <p> <b>Description.</b> Sponge encrusting to massive. Surface hispid with inconspicuous oscules. Colour green <i>in vivo</i>, creamy white in ethanol 70% (Fig. 2). Consistency soft, compressible and fragile. <b>Spicules.</b> Megascleres oxeas (232–320.3–406 / 8–11.5–16 µm), smooth, straight to slightly curved, gradually pointed (Fig. 3A); microscleres absent; gemmuloscleres acanthoxeas (105–152.2–193 / 5–6.9 –10 µm) (Fig. 3B,D) and acanthostrongyles (77– 123.3–177 / 5–6.6–10 µm), straight shaft, entirely spined with a variable number of spines, usually more abundant and larger at the tips (Fig. 3C,E). Spines straight (predominantly) or curved (rarely), curved ones occur mainly towards the center of the spicule; straight ones in the center of the spicule. Gemmules (533–700.3–867 µm in diameter) abundant, spherical, scattered throughout the sponge body (Fig. 4A, B). Foramen simple, short tube without colar, contained inside a conical concavity of the pneumatic layer (Fig. 4C). Gemmular theca tri-layered: thin inner layer, thick pneumatic layer and inconspicuous outer layer (Fig. 4D). Gemmuloscleres radially embedded in the gemmular theca, emerging from the inner layer according to their different levels of insertion (Fig. 4B).</p> <p> <b>Ecology.</b> Specimens were collected on rocky substrate in shallow and turbid waters, with depth ranging from 10 cm to 1 m. Gemmules were often abundant.</p> <p> <b>Etymology.</b> The specific epithet refers to the type locality, at Chapada Diamantina, northeast Brazil.</p>Published as part of <i>Calheira, Ludimila & Pinheiro, Ulisses, 2018, A new species of Anheteromeyenia (Porifera, Demospongiae) with an emended diagnosis of the genus, pp. 129-136 in Zootaxa 4378 (1)</i> on pages 131-133, DOI: 10.11646/zootaxa.4378.1.9, <a href="http://zenodo.org/record/1168138">http://zenodo.org/record/1168138</a&gt

Anheteromeyenia Schroder 1927

Genus <i>Anheteromeyenia</i> Schröder, 1927 <p> <i>Heteromeyenia</i> (<i>Anheteromeyenia</i>): Schröder 1927: 108 (part).</p> <p> <i>Anheteromeyenia</i>: De Laubenfels 1936: 36 (part), Penney & Racek 1968:114 (part), Ricciardi & Reiswig 1993: 667 (part), Volkmer-Ribeiro 1996: 32, Volkmer-Ribeiro 2007: 118, Manconi & Pronzato 2002: 929 (part), 2005: 3235, Buso <i>et al</i>. 2012: 148.</p> <p> <i>Radiospongilla</i>: Bonetto & Ezcurra de Drago 1970: 39 (part), De Rosa-Barbosa 1984: 130 (part)</p> <p> <b>Emended diagnosis.</b> Encrusting Spongillidae. Ectosomal skeleton thick. Choanosomal skeleton formed by an irregular network of megascleres with unispicular tracts. Spongin sparse. Megascleres in one category (acanthoxeas or smooth oxeas) or two categories (alfa megascleres, acanthoxeas or smooth oxeas; and beta megascleres, acanthoxeas and acanthostrongyles). Microscleres absent. Gemmular theca tri-layered. Gemmuloscleres pseudobirotules, acanthoxeas, and acantostrongyles, radially embedded in the gemmular theca (modified from Buso <i>et al</i>. 2012).</p> <p> <b>Remarks.</b> The genus was redefined by Volkmer-Ribeiro (1996) who included species with acanthoxeas as megascleres, and irregularly birotulated gemmuloscleres in two categories of length. Manconi & Pronzato (2002) included acanthoxea megascleres and pseudobirotule gemmuloscleres in the diagnosis of <i>Anheteromeyenia</i>. Buso <i>et al</i>. (2012) redescribed the genus and stated that two categories of megascleres may be present: alfa megascleres, spiny or smooth amphioxeas, and beta megascleres, spiny amphioxeas to amphistrongyles, and irregularly birotulated gemmuloscleres. Here, we emended the diagnosis of <i>Anheteromeyenia</i> to include smooth oxeas as megascleres (found in the new species described here) and gemmuloscleres, acanthoxeas and acanthostrongyles, that Volkmer-Ribeiro (1996) and Buso <i>et al</i>. (2012) named irregularly birotulated. The nomenclature of the gemmulosclere was defined following the classification proposed by Manconi & Pronzato (2002). In addition, we consider that the oxeas and strongyles described for <i>Anheteromeyenia</i> by Buso <i>et al</i>. (2012) are amphioxeas and amphistrongyles, respectively. The underlined words correspond to the modifications made in the diagnosis.</p> <p> <b>Type species:</b> <i>Spongilla argyrosperma</i> Potts, 1880: 357 (by subsequent designation; Penney & Racek 1968).</p>Published as part of <i>Calheira, Ludimila & Pinheiro, Ulisses, 2018, A new species of Anheteromeyenia (Porifera, Demospongiae) with an emended diagnosis of the genus, pp. 129-136 in Zootaxa 4378 (1)</i> on page 131, DOI: 10.11646/zootaxa.4378.1.9, <a href="http://zenodo.org/record/1168138">http://zenodo.org/record/1168138</a&gt

A new species of Anheteromeyenia (Porifera, Demospongiae) with an emended diagnosis of the genus

Calheira, Ludimila, Pinheiro, Ulisses (2018): A new species of Anheteromeyenia (Porifera, Demospongiae) with an emended diagnosis of the genus. Zootaxa 4378 (1): 129-136, DOI: https://doi.org/10.11646/zootaxa.4378.1.

Des sanidasters chez les éponges d’eau douce : une spicule inattendue chez le genre birotulées <i>Corvoheteromeyenia</i> Ezcurra de Drago, 1979

Corvoheteromeyenia Ezcurra de Drago, 1979 est trouvé exclusivement dans la région néotropicale, où elle est connue par deux espèces: C. australis (Bonetto &amp; Ezcurra de Drago, 1966) et C. heterosclera (Ezcurra de Drago, 1974). Le genre est caractérisé par la présence de gemmuloscleres birotulées insérées radialement dans la gemmule ; de mégasclères uniquement composées d’oxes, occasionnellement couvertes par des microépines ; et des microsclères pseudobirotulées présentes en deux séries distinctes. Douze spécimens, appartenant au genre Corvoheteromeyenia, ont été échantillonnés dans le bassin du São Francisco (Bahia, Brésil). À partir de ce matériel, nous signalons l’espèce C. heteroscleres pour le bassin du São Francisco. De plus, nous décrivons une nouvelle espèce de Corvoheteromeyenia qui diffère des autres espèces du genre par la présence de gemmulosclères sanidasters. Ces sanidasters ont une morphologie intermédiaire entre les formes birotulées et les formes de bâtonnet (acanthostrongyles). La présence de gemmulosclère sanidasters pourrait être interprêtée comme une malformation due aux conditions environnementales, puisque des malformations des gemmulosclères ont déjà été observées en conditions expérimentales, quand certaines éponges d’eau douce étaient exposées à des métaux lourds. Cependant, seulement 50 % des gemmulosclères étaient alors malformées, alors que chez C. sanidastosclera n. sp. 100 % des gemmulosclères sont sanidasters. Nous ne croyons donc pas que la morphologie de ces spicules soit un résultat d’une exposition aux composés chimiques dans l’environnent. Nos résultats renforcent l’hypothèse de Penney &amp; Racek (1968) selon laquelle la séparation des Spongillidae Gray, 1867 en deux groupes d’après la forme de leur gemmulosclère comme proposée par Vejdovsky (1887) n’est plus justifiée.Corvoheteromeyenia Ezcurra de Drago, 1979 is exclusively known from Neotropical Region with two species recorded: C. australis (Bonetto &amp; Ezcurra de Drago, 1966) and C. heterosclera (Ezcurra de Drago, 1974). The genus is characterized by the presence of birotuled gemmuloscleres inserted radially embedded in the gemmule, by megascleres which are exclusively oxeas, occasionally sparsely microspined and pseudobirotuled microscleres present in two distinct series. A total of twelve specimens were collected in São Francisco Basin (Bahia State, Brazil) and identified as belonging to C­orvoheteromeyenia. Based on this material, we record C. heterosclera for São Francisco Basin. Additionally, we describe a new species of Corvoheteromeyenia that differs from other species of genus by having gemmulosclere sanidaster. Sanidaster display an intermediate morphology between the birotule and rodlike (acanthostrongyle) spicular type. The gemmulosclere sanidaster found here could be interpreted as malformations due to environmental conditions, since malformations in gemmuloscleres had previously been observed in experimental conditions in some freshwater sponges exposed to heavy metal. However, in these conditions only 50% of gemmoscleres were malformed, and in C. sanidastosclera n. sp., 100% of gemmoscleres were sanidasters. Thus we do not believe that this morphology of spicules was the result of exposure to chemical compounds in the environment. This result reinforces the idea of Penney &amp; Racek (1968) that the segregation of Spongillidae Gray, 1867 into two groups based on the form of gemmoscleres as proposed by Vejdovsky (1887) is no longer justified.</p

Heteromeyenia insignis Weltner 1895

&lt;i&gt;Heteromeyenia insignis&lt;/i&gt; Weltner, 1895 &lt;p&gt; &lt;b&gt;Synonymy.&lt;/b&gt; For synonymy see Muricy &lt;i&gt;et al.&lt;/i&gt; (2011).&lt;/p&gt; &lt;p&gt; &lt;b&gt;Type Material:&lt;/b&gt; Holotype. ZMB Por 2148 (not seen). Museum f&uuml;r Naturkunde, Berlin.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Material studied.&lt;/b&gt; MNRJ 0 0 0 2, Atl&acirc;ntico Sul Basin, Rio Grande do Sul State, Brazil.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Diagnosis.&lt;/b&gt; Species of &lt;i&gt;Heteromeyenia&lt;/i&gt; characterized by the presence of acanthoxea megascleres with tuberculated spines and acanthoxea microscleres; two categories of gemmuloscleres: birotules with microspined margins of rotules and spined shaft, and pseudobirotules with large apical spines disposed orthogonally to the shaft, with sharp terminations bent as a hawk&rsquo;s bill, and spined shaft.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Description.&lt;/b&gt; Sponge encrusting. Surface hispid with protuberances. Oscules irregularly scattered over the surface of the sponge. Colour is bright green &lt;i&gt;in vivo&lt;/i&gt; and creamy white when dry (Fig 4). Consistency soft and gelatinous in life, fragile in the dry condition. According to Volkmer-Ribeiro (1963) the species can be confused with algae when touched. Ectosomal skeleton with scattered microscleres. Choanosomal skeleton is an irregular network of paucispicular parallel fibres. Megascleres and microscleres are isolated and scattered randomly. Megascleres acanthoxeas (190&ndash;261&ndash;303 / 12&ndash;15 &micro;m) with tuberculated microspines, straight or slightly curved, sharpening gradually towards the apices (Fig. 5 a,b). Microscleres acanthoxeas (35&ndash;60&ndash;75 / 3&ndash;5 &micro;m) with straight or curved, simple or compound spines. Curved spines occur near the tips of the spicule, with centripetal direction and are always simple. Straight spines occur in the median portion of the spicule, can be simple (rare) or compound (predominant). The compound spines have a bouquet-like structure, where the primary spine supports the secondary spines (Fig. 5 c,d). Gemmuloscleres in two categories: pseudobirotules (fig. 5e) (85&ndash;105&ndash;125 / 5&ndash;8 // 15&ndash;25 &micro;m) and birotules (fig. 5f) (73&ndash;81&ndash;105 / 5&ndash;8 // 10&ndash;18 &micro;m), in both the shaft present numerous conical spines (Fig. 5 e,f). Pseudobirotules with large apical spines (pseudorotules) disposed orthogonally to the shaft, with sharp terminations bent as a hawk&rsquo;s bill. The teeth project from the center of the pseudorotule and can be simple or anastomosing (Fig. 5 g). Birotules with smooth surface rotules, flattened discs with marginal microspines bent towards the other rotule (Fig. 5 h). Both are found in similar proportions in the gemmules. Gemmules (450&ndash;500 &micro;m) abundant, isolated or in groups, scattered throughout the sponge body, spherical, with the side of the foramen variously flattened (Fig. 6 a). Foramen with irregular shape. Gemmular theca tri-layered with gemmuloscleres radially embedded. Pneumatic layer well developed (Fig. 6 b,c).&lt;/p&gt; &lt;p&gt; &lt;b&gt;Ecology.&lt;/b&gt; The specimen was found encrusting small submerged pebbles.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Distribution.&lt;/b&gt; Brazil: Santa Catarina and Rio Grande do Sul States: South Atlantic Basin.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Remarks.&lt;/b&gt; Weltner (1895) described &lt;i&gt;H. insignis&lt;/i&gt; based on material collected by Fritz M&uuml;ller from Blumenau (Santa Catarina State). Probably, this specimen was collected in the Itaja River, since all the sponges deposited in the collection of Museu de Zoologia of Universidade de S&atilde;o Paulo (MZUSP), that were collected by Fritz M&uuml;ller, had been recorded from this locality. Volkmer-Ribeiro (1963) redescribed the species based on material collected at Dom Pedro I stream, in S&atilde;o Francisco de Paula (Rio Grande do Sul State), to complete the extremely succinct description offered by Weltner (1895). Her material was deposited at Museu Nacional (MNRJ 0002), and is reexamined here.&lt;/p&gt; &lt;p&gt; Ezcurra de Drago (1979) proposed the synonymization of &lt;i&gt;H. insignis&lt;/i&gt; and &lt;i&gt;H. baileyi&lt;/i&gt;, arguing that the material used for redescription of the former (MNRJ 0002) also has hook-like spines in the rotules, a trait considered by Volkmer-Ribeiro (1963) as a distinctive character between both species. This synonymy was completely ignored in subsequent works of other authors (De Rosa-Barbosa 1984; Volkmer-Ribeiro &lt;i&gt;et al&lt;/i&gt;. 1988; Batista &lt;i&gt;et al&lt;/i&gt;. 2007).&lt;/p&gt; &lt;p&gt; Kilian &amp; Wintermann-Kilian (1976) described &lt;i&gt;Heteromeyenia horsti&lt;/i&gt; from material collected in Chile. Comparison of the description and images available of this species (Kilian &amp; Wintermann-Kilian 1976; Ezcurra de Drago 1979) with &lt;i&gt;H. insignis&lt;/i&gt; does not reveal any significant differences. The size and morphology of the spicules are identical. It is possible that both species are synonymous, but to confirm this hypothesis it is necessary to analyze the type material of &lt;i&gt;H. horsti&lt;/i&gt;, which was not possible at this moment.&lt;/p&gt; &lt;p&gt; This is the first work providing scanning electron micrographs of the complete set of spicules of &lt;i&gt;Heteromeyenia insignis&lt;/i&gt;. Ezcurra de Drago (1979) offered images of the gemmuloscleres only. When we compare &lt;i&gt;H. insignis&lt;/i&gt; (MNRJ 0002) and the redescription of the lectotype of &lt;i&gt;H. baileyi&lt;/i&gt; (see Manconi &amp; Pronzato 2002; Fig. 38), reveals characteristics that justify &lt;i&gt;H. insignis&lt;/i&gt; as a valid species. In &lt;i&gt;H. baileyi&lt;/i&gt; the shaft of gemmuloscleres can be smooth or with a few spines (see Manconi &amp; Pronzato 2002; Fig. 38i,j), while &lt;i&gt;H. insignis&lt;/i&gt; has the shaft completely covered by spines (Fig. 5 e,f). The teeth of pseudorotules in &lt;i&gt;H. baileyi&lt;/i&gt; have tips bent backwards (180 angle, Manconi &amp; Pronzato 2002; Fig. 38k), whereas in &lt;i&gt;H. insignis&lt;/i&gt;, this bending is more discreet, with tips resembling a hawk&rsquo;s bill, pointing towards the other pseudorotule (90 angle, Fig. 5 g).&lt;/p&gt; &lt;p&gt; Another character that could be useful to distinguish species of &lt;i&gt;Heteromeyenia&lt;/i&gt; is the morphology of microscleres. However, there is no SEM done of the type material of &lt;i&gt;H. baileyi&lt;/i&gt;, which precluded this comparison. Furthermore, previous studies on &lt;i&gt;Heteromeyenia&lt;/i&gt; did not discuss this character.&lt;/p&gt; &lt;p&gt; Finally, both species have a remarkably disjunct distribution: &lt;i&gt;Heteromeyenia baileyi&lt;/i&gt; is known from the Northern Hemisphere in Nearctic and Palearctic (US, Canada, Germany, Portugal, Spain, and Poland) and &lt;i&gt;H. insignis&lt;/i&gt; only from Neotropical Region (Brazil, and Argentina).&lt;/p&gt;Published as part of &lt;i&gt;Pinheiro, Ulisses, Calheira, Ludimila &amp; Hajdu, Eduardo, 2015, A new species of freshwater sponge, Heteromeyenia barlettai sp. nov. from an aquarium in São Paulo, Brazil (Spongillida: Spongillidae), pp. 351-363 in Zootaxa 4034 (2)&lt;/i&gt; on pages 357-361, DOI: 10.11646/zootaxa.4034.2.7, &lt;a href="http://zenodo.org/record/289843"&gt;http://zenodo.org/record/289843&lt;/a&gt

Heteromeyenia Potts 1881

Genus &lt;i&gt;Heteromeyenia&lt;/i&gt; Potts, 1881 &lt;p&gt; &lt;b&gt;Synonymy.&lt;/b&gt; For synonymy see Manconi &amp; Pronzato (2002).&lt;/p&gt; &lt;p&gt; &lt;b&gt;Diagnosis.&lt;/b&gt; Spongillidae with encrusting body shape. Choanosomal skeleton an irregular network of paucispicular parallel fibres and undefined secondary tracts. Sparse spongin. Megascleres and microscleres acanthoxeas. Gemmules free in the sponge body. Foramen circular, tube short or long, with or without filiform extensions. Gemmular theca tri-layered with gemmuloscleres radially embedded. Gemmuloscleres in one or two categories: birotules and pseudobirotules (sensu Batista &lt;i&gt;et al&lt;/i&gt;. 2007).&lt;/p&gt; &lt;p&gt; &lt;b&gt;Type Species:&lt;/b&gt; &lt;i&gt;Spongilla baileyi&lt;/i&gt; Bowerbank, 1863 (by subsequent designation; De Laubenfels 1936).&lt;/p&gt; &lt;p&gt; &lt;i&gt;Heteromeyenia barlettai&lt;/i&gt; &lt;b&gt;sp. nov.&lt;/b&gt;&lt;/p&gt; &lt;p&gt; &lt;b&gt;Type locality.&lt;/b&gt; Aquarium in S&atilde;o Paulo, S&atilde;o Paulo State, Paran&aacute; Basin, Brazil.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Type specimens: Holotype.&lt;/b&gt; UFPEPOR 1728. &lt;b&gt;Paratypes&lt;/b&gt;: UFPEPOR 1729 and UFPEPOR 1730 (collected together with the holotype).&lt;/p&gt; &lt;p&gt; &lt;b&gt;Diagnosis&lt;/b&gt;. Sponge encrusting to slightly massive, with megascleres and microscleres acanthoxeas; only one category of birotule gemmuloscleres, with exclusively smooth rotules, radially inserted in outer and pneumatic layers (theca) of the gemmule.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Description of holotype.&lt;/b&gt; UFPEPOR 1728 is encrusting measuring 6 cm 2. Colour is creamy white &lt;i&gt;in vivo&lt;/i&gt;, without colour change after preservation in ethanol. Megascleres acanthoxeas (250&ndash;280.3&ndash;310 / 8.8&ndash;9.9&ndash;12.5 &micro;m), microscleres acanthoxeas (63&ndash;76.6&ndash;88 / 3.8&ndash;5.0&ndash;6.3 &micro;m), gemmuloscleres birotules (58&ndash;61.1&ndash;68 / 5&ndash;5.6&ndash;7.5 / 17.5&ndash;18.0&ndash;20 &micro;m), gemmules scattered throughout the sponge body (396&ndash;488&ndash;600 &micro;m in diameter) (Table 1).&lt;/p&gt; &lt;p&gt; &lt;b&gt;Description.&lt;/b&gt; Sponges encrusting to slightly massive, 3&ndash;5 mm thick, 3 cm wide. Surface hispid with tubular and translucent oscules. Colour creamy white &lt;i&gt;in vivo&lt;/i&gt;, without colour change after preservation in ethanol (Fig. 1).&lt;/p&gt; &lt;p&gt;Consistency soft to fragile. Megascleres acanthoxeas (235&ndash;279.9&ndash;332 / 8.1&ndash;9.7&ndash;12.5 &micro;m), slightly curved, with conical microspines scattered in the median portion (Fig. 2 a,b). Microscleres acanthoxeas (63&ndash;78.3&ndash;106 / 3.8&ndash;5.3&ndash; 6.4 &micro;m), straight to curved, entirely spined with a variable number of spines, usually more abundant and larger in the median portion of the shaft. Spines can be straight or curved, curved ones are simple and occur mainly towards the center of the spicule; straight ones are simple (rarely) or compound (predominantly), occur in the center of the spicule. The compound spines have a bouquet-like structure, where the primary spine supports the secondary ones (Fig. 2 c,d). Gemmulosclere birotules (Fig. 2 e) (58&ndash;62.9&ndash;71 / 5.0&ndash;6.6&ndash;9.7 // 16&ndash;18.5&ndash;23 &micro;m), radially inserted in the theca of gemmules; shaft with conical spines (simple or compound) (Fig. 2 f). Rotules are smooth, circular, convex and identical, with microspines on their margins, inserted perpendicularly, erect or recurved in either direction (Fig. 2 g). Gemmules (396&ndash;488&ndash;600 &micro;m) rare, small, spherical, scattered throughout the sponge body (Fig. 3 a). Foramen short, with rosette-like collar from some gemmuloscleres radially inserted. Gemmular theca trilayered, well developed, with irregular spaces, gemmuloscleres radially inserted in the pneumatic layer, inner layer with compact spongin, outer layer irregularly outlined (Fig. 3 b,c).&lt;/p&gt; &lt;p&gt;Species/ Specimens Locality Megasclere Microscleres Acanthoxea&lt;/p&gt; &lt;p&gt;Acanthoxea&lt;/p&gt; &lt;p&gt;Holotype (UFPEPOR 1728) SP, Brazil 250&ndash;280.3&ndash;310 / 63&ndash;76.6&ndash;88 / 8.8&ndash;9.9&ndash;12.5 3.8&ndash;5&ndash;6.3&lt;/p&gt; &lt;p&gt;Paratype (UFPEPOR 1729) SP, Brazil 245&ndash;280&ndash;332 / 64&ndash;76.9&ndash;87 / 8.1&ndash;9.6&ndash;11.3 4.8&ndash;5.3&ndash;6.4 Paratype (UFPEPOR 1730) SP, Brazil 235&ndash;279.3&ndash;319 / 64&ndash;81.3&ndash;106 / 8.1&ndash;9.5&ndash;9.7 4.8&ndash;5.7&ndash;6.4&lt;/p&gt; &lt;p&gt;continued.&lt;/p&gt; &lt;p&gt;Species/ Gemmuloscleres Gemmules Specimens Birotulate Pseudobirotulate&lt;/p&gt; &lt;p&gt;Holotype (UFPEPOR 1728) 58&ndash;61.1&ndash;68 / &ndash; 396&ndash;488&ndash;600&lt;/p&gt; &lt;p&gt;5&ndash;5.6&ndash;7.5 // 17.5&ndash;18&ndash;20&lt;/p&gt; &lt;p&gt;Paratype (UFPEPOR 1729) 58&ndash;64.6&ndash;71 / &ndash; &ndash; 6.4&ndash;7.5&ndash;9.7 // 16&ndash;18.9&ndash;23&lt;/p&gt; &lt;p&gt;Paratype (UFPEPOR 1730) &ndash; &ndash; &ndash;&lt;/p&gt; &lt;p&gt; &lt;b&gt;Ecology.&lt;/b&gt; According to the aquarium owner, Mr. Fernando Barletta, an ideal condition for the development of these sponges is a pH 7.5 or higher. But when the specimens are subjected to lower pH (acidic conditions), the sponges produce gemmules and die. The sponges prefer the lentic sites in the aquarium, and can be found at leaves and roots of aquatic plants, crevices of woods, and the plastic filter, but not on the stones.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Etymology.&lt;/b&gt; The chosen specific name honors Fernando Barletta, the owner of the aquarium whose curiosity permitted the discovery of the new species.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Remarks.&lt;/b&gt; Batista &lt;i&gt;et al&lt;/i&gt;. (2007) redefined the genus to allocate &lt;i&gt;Heteromeyenia cristalina&lt;/i&gt;, which has only one category of gemmulosclere, differing from all other congeners that have two categories. Thus, by sharing this character, &lt;i&gt;H. cristalina&lt;/i&gt; is the species most similar to &lt;i&gt;H. barlettai&lt;/i&gt; &lt;b&gt;sp. nov.&lt;/b&gt; However, the new species differs from &lt;i&gt;H. cristalina&lt;/i&gt; by its gemmuloscleres which have smooth rotules, in contrast to the rotules of &lt;i&gt;H.cristalina&lt;/i&gt; that are entirely covered in microspines. Futhermore, there are differences in the pattern of spination of the shaft of gemmuloscleres. &lt;i&gt;Heteromeyenia barlettai&lt;/i&gt; &lt;b&gt;sp. nov.&lt;/b&gt; has spines that are predominantly compound, against predominantly simple spines observed on the shafts of gemmuloscleres of &lt;i&gt;H. cristalina&lt;/i&gt;. Although Batista &lt;i&gt;et al&lt;/i&gt;.&lt;/p&gt; &lt;p&gt; (2007) did not describe compound spines, these can be observed in SEM images of gemmuloscleres (see Batista &lt;i&gt;et al.&lt;/i&gt; 2007; Figs. 21&ndash;22). Another difference derives from the sizes of the spicules, as the megascleres, microscleres and gemmuloscleres of &lt;i&gt;H. cristalina&lt;/i&gt; are larger than those of the new species (Table 1,2).&lt;/p&gt; &lt;p&gt;. &lt;i&gt;latitenta&lt;/i&gt; (Potts, 1881) (1) PensII˅anI&ordf;' USA 265&ndash;285 / 8&ndash;11 85 &ndash;100 / 2&ndash;3 50 &ndash;55 60&ndash;78 &ndash;&lt;/p&gt; &lt;p&gt;. &lt;i&gt;stepanowii&lt;/i&gt; (Dysbowsky, 1884) (1) Czechoslovakia, 180&ndash;310 / 8&ndash;11 78 &ndash;88 / 2&ndash;3 58 &ndash;65 75&ndash;88 430&ndash;520&lt;/p&gt; &lt;p&gt;Germany, Poland,&lt;/p&gt; &lt;p&gt;Russia, China,&lt;/p&gt; &lt;p&gt;Japan, New South&lt;/p&gt; &lt;p&gt;Wales&lt;/p&gt; &lt;p&gt;. &lt;i&gt;tentasperma&lt;/i&gt; (Potts, 1880) (1) Wisconsin, USA 260&ndash;280 / 7&ndash;10 75 &ndash;80 / 2-3 50 &ndash;55 65&ndash;72 420&ndash;450&lt;/p&gt; &lt;p&gt;. &lt;i&gt;tubisperma&lt;/i&gt; (Potts, 1881) (1) Canada 190&ndash;230 / 7&ndash;10 85 &ndash;90 / 2-3 40 &ndash;48 60&ndash;70 500&ndash;550&lt;/p&gt; &lt;p&gt;. &lt;i&gt;barlettai&lt;/i&gt; &lt;b&gt;sp. nov.&lt;/b&gt; (5) SP, Brazil 235&ndash;279.9&ndash;332 / 63&ndash;78.3&ndash;106 / 58&ndash;62.9&ndash;71 / &ndash; 396&ndash;488&ndash;600&lt;/p&gt; &lt;p&gt;8.1&ndash;9.7&ndash;12.5 3.8&ndash;5.3&ndash;6.4 5&ndash;6.6&ndash;9.7 // 16&ndash;18.5&ndash;23&lt;/p&gt; &lt;p&gt; REFERENCES: (1) Penney &amp; Racek (1968); (2) Batista &lt;i&gt;et al.&lt;/i&gt; (2007); (3) Kilian &amp; Wintermann-Kilian (1976); (4) Weltner (1895); (5) current work.&lt;/p&gt; &lt;p&gt; The natural environment of &lt;i&gt;Heteromeyenia barlettai&lt;/i&gt; &lt;b&gt;sp nov&lt;/b&gt;. is unknown. The macrophytes of the aquarium came from fish farm tanks near the Guarapiranga Reservoir, one of the main water sources for the city of S&atilde;o Paulo. The aquarium water was collected from the same reservoir. Probably, the gemmules were carried by the water or came attached to the macrophytes.&lt;/p&gt;Published as part of &lt;i&gt;Pinheiro, Ulisses, Calheira, Ludimila &amp; Hajdu, Eduardo, 2015, A new species of freshwater sponge, Heteromeyenia barlettai sp. nov. from an aquarium in São Paulo, Brazil (Spongillida: Spongillidae), pp. 351-363 in Zootaxa 4034 (2)&lt;/i&gt; on pages 352-357, DOI: 10.11646/zootaxa.4034.2.7, &lt;a href="http://zenodo.org/record/289843"&gt;http://zenodo.org/record/289843&lt;/a&gt