Helmut Lehnert

Cladorhiza corona sp. nov. (Porifera : Demospongiae : Cladorhizidae) from the Aleutian Islands (Alaska)

A new species of Cladorhizidae, from the Aleutian Islands is described and compared with all known species of Cladorhiza worldwide. Cladorhiza corona sp. nov. has a unique growth form with two planes of diierently shaped appendages. Appendages are inserted directly at the stalk; a spherical or conical body at the stalk is lacking. It is the only species reported where diierent spicule types occur in three morphologically diierent areas of the sponge. The spiculation of the basal plate is characterized by the occurrence of short, thick anisoxeas and the lack of anisochelae. Anisochelae are found in the stalk and the basal appendages only. Flattened sigmancistras and (sub-)tylostyles are restricted to the crown. The arrangement of spicules is diierent in the basal plate, the stalk with the basal appendages, and in the distal appendages. The dimensions and combination of spicule types separate C. corona sp. nov. from all known members of the genus.

Erylus aleuticus sp. nov. (Porifera: Demospongiae: Astrophorida: Geodiidae) from the Aleutian Islands, Alaska, USA

A new species of Erylus from the Aleutian Islands is described. This is the ¢rst record of the genus from the Aleutian Islands. The new species diiers from all other known species of Erylus in the presence of diierent types of monaxonic megascleres, ranging from oxeas, strongyles, styles, tylostyles to tylotes, often with unequal ends and irregular modi¢cations of these types. The lack of a secondary category of asters is also unusual for the genus.

A comprehensive inventory of the Gulf of Alaska sponge fauna with the description of two new species and geographic range extensions

Two new species, Hamacantha (Vomerula) cassanoi n. sp. and Prosuberites salgadoi n. sp., are described from the eastern Gulf of Alaska in the North Pacific Ocean. These are the first records of the genera Hamacantha and Prosuberites from Alaska. We also report two geographic range extensions for the region. Geodia japonica Sollas, 1888 was previously known only from Japan and is now recorded from the Gulf of Alaska. We also document the first record of Rhizaxinella cervicornis Thiele, 1898 from the Gulf of Alaska. Our comprehensive inventory of the sponge fauna of the Gulf of Alaska confirms the presence of 52 taxa with an additional 38 taxa suspected of occurring in the region. This is a much lower number of species than that recorded from neighbouring regions like the Aleutian Islands and British Columbia.

Craniella sputnika sp. nov. (Porifera: Spirophorida: Tetillidae) from the Aleutian Islands, Alaska, with suggested nomenclatural changes for the genera Tetilla and Craniella

A new species of Craniella from the Aleutian Islands is described. Craniella sputnika sp. nov. differ from all other species of Craniella in its habitus, absence of microscleres and size of spicules. The name refers to its resemblance to Earths first artificial satellite, due to its spherical body with long spines. The new species was observed growing on another demosponge, Myxilla sp. We propose transferring two species currently in Craniella to Tetilla ( Craniella ellipsoidea Hoshino, 1982 and Craniella laminaris (George & Wilson, 1919)) and two subspecies ( Craniella globosa anamonaena Tanita, 1968 and Craniella laminaris symmetrica (Wilson, 1931)) from Craniella to Tetilla . As Craniella globosa anamonaena Tanita, 1968, is actually a species of Tetilla we suggest raising the subspecies to species rank as Tetilla anamonaena . Conversely we think that two species, Tetilla ovata (Thiele, 1898) and Tetilla hamatum Koltun, 1966 should be transferred to Craniella .

Two new species of Suberitida (Porifera, Heteroscleromorpha) from the Bering Sea

Two new species, Plicatellopsis borealis and Spongosorites beringensis, from the Bering Sea are described; both belong to genera previously not reported from the area. The genus Plicatellopsis, Burton, 1932 (Porifera, Suberitida, Suberitidae) contains five valid species, all recorded from the southern hemisphere. The record of P. borealis n. sp. from the Bering Sea is consequently the first record of the genus from the northern hemisphere. The genus Spongosorites Topsent, 1896 (Porifera, Suberitida, Halichondriidae) contains 22 valid species but none reported from the North Pacific Ocean, Bering Sea or the Arctic Ocean. The geographically closest records are six species occurring in the North Atlantic Ocean. So the description of Spongosorites beringensis n.sp. is the first record of the genus in the region.

New species of sponges (Porifera, Demospongiae) from the Aleutian Islands and Gulf of Alaska.

Ten new species of demosponges, assigned to the orders Poecilosclerida, Axinellida and Dictyoceratida, discovered in the Gulf of Alaska and along the Aleutian Island Archipelago are described and compared to relevant congeners. Poecilosclerida include Cornulum globosum n. sp., Megaciella lobata n. sp., M. triangulata n. sp., Artemisina clavata n. sp., A. flabellata n. sp., Coelosphaera (Histodermion) kigushimkada n. sp., Stelodoryx mucosa n. sp. and S. siphofuscus n. sp. Axinellida is represented by Raspailia (Hymeraphiopsis) fruticosa n. sp. and Dictyoceratida is represented by Dysidea kenkriegeri n. sp. The genus Cornulum is modified to allow for smooth tylotes. We report several noteworthy biogeographical observations. We describe only the third species within the subgenus Histodermion and the first from the Indo-Pacific Region. Additionally, the subgenus Hymerhaphiopsis was previously represented by only a single species from Antarctica. We also report the first record of a dictyoceratid species from Alaska. The new collections further highlight the richness of the sponge fauna from the region, particularly for the Poecilosclerida.

Two new species of sponges (Porifera, Demospongiae) from the Aleutian Islands, Alaska

Two new demosponges, Megaciella pituitosa and Cladocroce toxifera, are described from the Aleutian Islands, fostering our contention that the region is a hotspot of poriferan biodiversity. Seven of the thirteen species of Megaciella now known worldwide occur in the Sea of Okhotsk or around the Aleutian Islands. Similarly, five of the sixteen species of Cladocroce known worldwide occur in Alaska. Megaciella pituitosa sp. nov. possesses two categories of choanosomal styles and spicules of different sizes that differentiate it from all known congeners. Cladocroce toxifera sp. nov. differs from all known congeners by possessing toxa and an ectosomal tangential arrangement of oxeas.