Middorsal Spines Research Articles

Brucerolis gen. n., and Acutiserolis Brandt, 1988, deep-water southern genera of isopods (Crustacea, Isopoda, Serolidae)

Acutiserolis Brandt is rediagnosed (coxal dorsal plates 2–5 slot into each other with no aperture between; coxal plate 6 has a blunt process on its anterior margin slotting into a groove on coxa 5 and isolating an oval aperture; with prominent middorsal pereonal and pleonal spines; pleotelson with a sharp middorsal keel, upturned posteriorly; and sharply defi ned longitudinal sublateral keels ending acutely) and confi ned to the type species, Serolis spinosa Kussakin, 1967, and two species of Cuspidoserolis Brandt, 1988 syn. n. Brucerolis gen. n., (type species Brucerolis nowra sp. n.) is erected for species previously assigned to Acutiserolis but from which it diff ers in having the coxal dorsal plates 2–6 interacting only by means of key-like lobes, coxal plate 6 exceeding the pleotelson by at least the pleotelson length, middorsal spines being absent or obscure, and the pleotelson lacking ridges and keels. Four other species are included: Brucerolis bromleyana (Willemoes-Suhm, 1876); B. cidaris (Poore & Brandt, 1997); B. macdonnellae (Menzies, 1962); and possibly B. maryannae (Menzies, 1962).

A new kinorhynch genus from the Antarctic deep sea and a new species of Cephalorhyncha from Hawaii (Kinorhyncha: Cyclorhagida: Echinoderidae)

A new species of a new kinorhynch genus with affinities to the Echinoderidae and a new species of Cephalorhyncha are described. Polacanthoderes martinezi gen. et sp. nov. was collected during the German ANDEEP-1 cruise at 2290 m depth north of the South Shetland Islands in the Southern Atlantic Ocean, approximately 170 km north of the Antarctic Peninsula. Polacanthoderes is characterized by the presence of a first trunk segment consisting of a complete cuticular ring, and by each of the following ten segments consisting of one tergal and two sternal plates. Cuticular hairs and perforation sites are absent, but spines are present in middorsal, subdorsal, laterodorsal, midlateral, lateral accessory, lateroventral, ventrolateral and ventromedial series on segments 4–10. The ventral side of segment 1 has a very strong and conspicuous pectinate fringe, whereas fringes are indistinct or absent on posterior segment margins of the following segments. Due to segment 1 being composed of a closed ring and the following segments of a tergal and two sternal plates, as well as to the presence of aligned middorsal spines and lateral terminal spines but absence of a midterminal spine, Polacanthoderes is assigned to the family Echinoderidae. Cephalorhyncha liticola sp. nov. was collected in the intertidal zone of a high energy beach on the northeast coast of Oahu, Hawaii. The species is characterized by the sternal plate of segment 2 being incompletely separated anteriorly by a midventral fissure. Middorsal spines are present on segments 4–8, ventrolateral spines on segment 2, lateroventral spines on segments 5–9, lateral accessory spines on segment 8, and laterodorsal spines on segment 10. In addition, there are special sensory spots with conspicuous marginal cuticular hairs on segments 1–3, and very long pectinate fringes on the sternal plates of segments 3–10. The partly subdivided sternal plates on segment 2 show the species to belong to the echinoderid genus Cephalorhyncha.

Tubulideres seminoli gen. et sp. nov. and Zelinkaderes brightae sp. nov. (Kinorhyncha, Cyclorhagida) from Florida

One new kinorhynch genus and species and one new species from the genus Zelinkaderes are described from sandy sediment off Fort Pierce, Florida. The new genus and species, Tubulideres seminoli gen. et sp. nov. is characterized by the presence of the first trunk segment consisting of a closed ring, the second segment of a bent tergal plate with a midventral articulation and the following nine segments consisting of a tergal and two sternal plates. Cuspidate spines are not present, but flexible tubules are located on several segments, and in particular concentrated on the ventral side of the second segment. Middorsal spines are present on all trunk segments and are alternatingly offset to a position slightly lateral to the middorsal line. Zelinkaderes brightae nov. sp. is characterized by its spine formula in having middorsal spines on trunk segments 4, 6 and 8–11, lateroventral acicular spines on segment 2, lateral accessory cuspidate spines on segments 2 and 8, ventrolateral cuspidate spines on segments 4–6 and 9, lateroventral acicular spines present on segments 8 and 9, and midterminal, lateral terminal and lateral terminal accessory spines on segment 11. The spine formula of Z. brightae nov. sp. places it in a position in between Z. submersus and a clade consisting of Z. klepali and Z. floridensis. The new findings on Z. brightae nov. sp. have led us to propose an emended diagnosis for the genus.

A new species of Echinoderes from Florida (Kinorhyncha: Cyclorhagida)

A new kinorhynch, Echinoderes spinifurca, is described from the Atlantic coast off Fort Pierce, Florida. The species is characterized by the presence of middorsal spines on segments 6 to 10 and lateral spines/tubules on segments 4 and 7–12. The tergal furca (tergal extension) is extraordinarily long, constituting 9.3–12.9 percent of the trunk length, and this distinct character makes it easy to distinguish the species from all other species of Echinoderes. Echinoderes spinifurca occurs in shell gravel and mixed shell gravel with sand, and coexists with Echinoderes horni, Zelinkaderes sp., and two undescribed cyclorhagid taxa.

A revision of Heterosignum (Asellota, Isopoda, Paramunnidae) with descriptions of three new species

Three new species of Heterosignum are described from Japan. Heterosignum elegans sp. nov. differs from its congeners in having stout preorbital lobes on the head, very long lateral spine-like processes and eyestalks, and very long article 2 of male pleopod 2. Heterosignum ohtsukai sp. nov. is distinctive in having a marked stout mid-dorsal spine on the head, long mid-dorsal spines on the pereonites, and article 2 of antenna 1 with a distolateral protrusion. Heterosignum otsuchiensis sp. nov. has single lateral spine-like processes on pereonites 1-7 as in H. ohtsukai, but is distinguished from it in having short mid-dorsal spines on pereonites 1-7 and long basis of pereopod 1. Heterosignum mutsuensis Gamô, 1976 is redescribed using newly collected specimens. Coulmannia unicornis Kensley, 1976 is assigned to Heterosignum after careful examination of the types. The diagnosis of Heterosignum is emended to include all the five species so far recorded.

Taxonomic study of the kinorhyncha in Japan. III. Echinoderes sensibilis n. sp. (Kinorhyncha: Cyclorhagida) from Tanabe Bay.

A new species of echinoderid kinorhynch, Echinoderes sensibilis, is described and illustrated using light and electron microscopy. The specimens were collected from masses of the red algae Corallina pilulifera growing in intertidal pools in Tanabe Bay, Honshu Island, Japan. Diagnostic characters of E. sensibilis include the presence of middorsal spines on segments 6-10; lateral spines/tubules on segments 4, 7-12; remarkable trapezium-like subventral fields of minute cuticular hairs on segments 5-12. The positions of numerous sensory spots, large sieve areas, glandular tubes and the shape of terminal tergal and sternal extensions are also diagnostic. All taxonomic characters used for this description are illustrated by SEM. Echinoderes sensibilis constitutes the fifty-eight valid species of the genus Echinoderes and the fourteenth species described from the Pacific Ocean. This is the third representative of Pacific kinorhynchs found only in the intertidal zone and the first Pacific Echinoderes living on red macroalgae in intertidal pools.

Echinoderes aureus n. sp. (Kinorhyncha : Cyclorhagida) from Tanabe Bay (Honshu Island), Japan, with a Key to the Genus Echinoderes

A new species of echinoderid kinorhynch, Echinoderes aureus, is described and illustrated using a differential interference contrast microscope with Nomarski optics. The kinorhynchs were collected from washings of a brown alga, Padina arborescens Holmes, growing in tide pools in Tanabe Bay, Honshu Island, Japan. Diagnostic characters of E. aureus are the presence of middorsal spines on segments 6-10, lateral spines/tubules on segments 4 and 7-12, a pair of remarkably large subcuticular scars in a subventral position on segment 3, and an incomplete midventral articulation on segment 4. The positions of numerous sensory-glandular organs, the sizes of various lateral spines/tubules, and the shapes of the terminal tergal and sternal extensions are also diagnostic. Echinoderes aureus constitutes the 59th valid species of the genus Echinoderes and the 15th species described from the Pacific Ocean. This is the fourth representative of Pacific kinorhynchs found only in the intertidal zone and the second Pacific Echinoderes living on macroalgae in tide pools. A dichotomous key to all 59 species is provided.

Kinorhynchs from the Andaman Islands

Echinoderes andamanensis sp. nov. is described from the Andaman Islands (Bay of Bengal, Indian Ocean). Unlike most members of this genus, this new species lacks middorsal spines. It is further distinguished by the presence of lateral spines on segments 4, 10 and 11 in the female and 4, 10–12 in the inale. Collected with E. andamanensis were specimens of E. ehlersi previously known only from a single specimen collected in 1885 in Zanzibar. The Andaman Island females have shorter spines than the males. Additional species include Catena gerlachi, previously known only from Walcair, India. A single juvenile exuvium of Pynophyes sp. was also found. The taxonomic relationships of the species and other members of the genus are discussed.

First Records, Description, Distribution, and Notes on the Biology of Bathyraja richardsoni (Garrick) from the Northwest Atlantic

Eighteen Bathyraja richardsoni (Garrick 1961), 95–174 cm in total length were taken by bottom longline from southern Labrador to Georges Bank, 17 at 1810–2360 m, and one at 1370–1500 m. These are the first records for the western Atlantic. Studies of morphometries, of numbers, of form, and arrangement of spines, dermal denticles, and teeth, and of body color in these skates amplify the description of the species, known previously only from New Zealand (the holotype) and the northeast Atlantic (eight specimens). There is, however, appreciable variation in the distribution and abundance of dermal denticles between the new specimens and the holotype. These specimens also have middorsal caudal spines instead of the middorsal caudal row of fleshy oval structures (some with a central tubercle of enamel) of the holotype, which are related in this paper to scar areas from lost spines.Some information is provided on weight–length, liver weight, and fatness, vitamin A of liver oil, and length at sexual maturity. Food was mainly fish.The trematode Otodistomum veliporum occurred in 5 of 16 stomachs and the cestode Onchobothrium pseudouncinatum in 6 of 16 intestines. A copepod, tentatively identified as Lernaeopodina longimana, was found on the gills of one of five specimens.