Freshwater sponges (Porifera: Spongillidae) from Panamá

Aquatic habitats in the Republic of Panamá were examined for freshwater sponges during 21 Feb. to 6 March 1986. Eunapius carteri, Trochospongilla leidyi, and Trochospongilla horrida were found in the northern canal area. This is the first report of E. carteri and T. horrida from Central America, and the first record of E. carteri from the Western Hemisphere. Taxonomic characters used to distinguish T. leidyi and T. horrida from similar South American species are discussed.     

The taxonomic and ecological status of the environmentally restricted spongillid species of North America. IV. Spongilla heterosclerifera Smith 1918

The taxonomic status, present distribution and specific threats to the existence of the environmentally restricted freshwater sponge, Spongilla heterosclerifera Smith 1918 were investigated. This species, collected only from Oneida Lake, New York, has not colonized other habitats and continues to exhibit typical diagnostic characteristics, thus qualifying as a valid environmentally restricted species. Although the sponge presently colonizes two sites in the lake, both near the northwestern shore, the total absence of sponge fauna from other lake regions near more heavily populated areas of this species. Physicochemical data from Oneida Lake greatly extend the known environmental parameters of Spongilla heterosclerifera.     

pH and Eh on Aldabra Atoll 2. Intertidal photosynthetic microbial communities showing zonation

The taxonomic status of Ephydatia subtilis (Weltner) remains undetermined. Despite extensive collecting in the type locality, Lake Kissimmee, Florida, the species was not found. Stratospongilla penneyi sp. nov. is described utilizing spicular diagnosis, cytochemistry, and scanning electron microscopy. Physicochemical data from the type locality are presented and specific threats to the existence of the species are determined.     

The taxonomic and ecological status of the environmentally restricted spongillid species of North America. I. Spongilla sponginosa Penney 1957

The taxonomic validity, present distribution, and specific threats to the existence of the freshwater sponge,Spongilla sponginosa Penney were investigated. This species, reported only from the type locality, Week's Pond, Sumter County, South Carolina, has apparently been extirpated due to highly acidic pH levels in the pond water. Examination of holotype materials indicate some question of the validity of S. sponginosa as a distinct species.     

Abundance and microhabitats of freshwater sponges (Spongillidae) in a Danubean floodplain in Austria

1. This study examined the abundance and distribution of freshwater sponges (Spongillidae) at 32 sites in a floodplain on the Danube within the ‘Donau‐Auen’ National Park east of Vienna, Austria. Ranked from abundant to rare, the species inventory comprised Ephydatia fluviatilis, Spongilla lacustris, Ephydatia mülleri, Eunapius fragilis and Trochospongilla horrida. 2. The presence of hard substratum was essential for the growth of sponges. Timber stands near the water and drifting dead wood increased the abundance of E. fragilis, E. fluviatilis and E. mülleri, whereas stony substrata were important for S. lacustris. A small fraction of E. fluviatilis was collected from macrophytes (Phragmites). 3. Based on the area colonised, the abundance of S. lacustris, E. fragilis and E. fluviatilis was highest (94.2–100% of the total) in floodplain waters where hydrological connectivity with the Danube was low (0–6 days year⁻¹), whereas E. mülleri and T. horrida made up 20.3–35.9% of the total at sites connected for up to 179 days year⁻¹. Moreover, the area colonised by T. horrida at a current velocity >0.20 m s⁻¹ was larger than in the remaining species. Sites with E. mülleri and T. horrida had a higher silicon concentration (0.9 mg L⁻¹) than sites where the remaining three species were collected (0.4–0.6 mg L⁻¹). 4. In most species, the length of macroscleres (the larger spicules) was positively correlated with conductivity and negatively with pH. With respect to aberrant macroscleres, hooks were observed most frequently, whereas the proportion of centrotylotes (ie with the one on more globular swellings along the spicule) was lowest. 5. Freshwater sponges have a great deal of potential as bioindicators and restoration measures that improve floodplain connectivity will favour rare species, such as E. mülleri and T. horrida, while impairing others (e.g. E. fragilis, S. lacustris and E. fluviatilis).     

Molecular phylogeny of the freshwater sponges in Lake Baikal

The phylogenetic relationship of the freshwater sponges (Porifera) in Lake Baikal is not well understood. A polyphyletic and/or monophyletic origin have been proposed. The (endemic) Baikalian sponges have been subdivided into two families: endemic Lubomirskiidae and cosmopolitan Spongillidae. In the present study, two new approaches have been made to resolve the phylogenetic relationship of Baikalian sponges; analysis of (1) nucleotide sequences from one mitochondrial gene, the cytochrome oxidase subunit I (COI) and of (2) one selected intron from the tubulin gene. Specimens from the following endemic Baikalian sponge species have been studied; Lubomirskia baicalensis , Baikalospongia intermedia, Baikalospongia recta , Baikalospongia bacillifera and Swartschewskia papyracea . They are all grouped to the family of Lubomirskiidae. Sequence comparisons were performed with the ubiquitously distributed freshwater sponge Spongilla lacustris (family Spongillidae) as well as with one marine sponge, Suberites domuncula . A sequence comparison * * The sequences reported here are being deposited in the EMBL data base. of the mitochondrial COI gene revealed a monophyletic grouping of the endemic Baikalian sponges with S. lacustris as the most related species to the common ancestor. The sequences of the COI gene from B. recta , B. intermedia , B. bacillifera and L. baicalensis were found to be identical and separated from those of S. lacustris and S. papyracea . In a second approach, the exon/intron sequences framing the intron‐2 of the sponge tubulin gene were chosen for the phylogenetic analysis. The intron sequences were aligned and used for construction of a phylogenetic tree. This analysis revealed again a monophyletic grouping with S. lacustris as the closest related species to the common ancestor. It is concluded that the Baikalian sponges, which have been studied here, are of monophyletic origin. Furthermore, the data suggest that the endemic species S. papyracea is the phylogenetically oldest, extant, endemic Baikalian sponge species.     

The taxonomic and ecological status of the environmentally restricted Spongillid species of North America. II. Anheteromeyenia biceps (Lindenschmidt, 1950)

The taxonomic validity, present distribution, and specific threats to the existence of the freshwater sponge, Anheteromeyenia biceps (Lindenschmidt, 1950) were investigated. The species, reported only from the type locality, Bessey Creek and Maple River, two streams flowing into Douglas Lake, Michigan, is relegated to synonomy with Ephydatia mülleri. Habitat data from Bessey Creek and Maple River, particularly physicochemical data, greatly extend the known environmental parameters of Heteromeyenia tubisperma and Ephydatia mülleri.     

The effects of cadmium and mercury on gemmule formation and gemmosclere morphology in Ephydatia fluviatilis (Porifera : Spongillidae)

A laboratory study of the effects of cadmium and mercury on the freshwater sponge, Ephydatia fluviatilis, was conducted. Sponge cuttings were exposed to concentrations of cadmium or mercury which ranged from 1.000 to 0.001 ppm for one month. The responses exhibited by the specimens resulted in four groups characterized as follows: sponge colony survived and produced gemmules with normal gemmoscleres; sponge colony survived and produced gemmules with malformed gemmoscleres; sponge colony survived but did not gemmulate; sponge colony died. A direct discriminant functions analysis of the four sponge groups, metal concentrations and other chemical data established a highly significant correlation between increasing metal concentrations and amount of damage to the sponge.