ABSTRACT
Apseudomorph tanaidaceans from recent samples of the South China Sea benthos off Brunei have been examined. The habitats were sandy substrata from between 5 and 90 m depth. Fourteen species of the four families considered here were discovered. A new species of Tanapseudes is described. The distribution of Phoxokalliapseudes gobinae is analyzed. Biropalostoma goofi is recorded for the first time in Brunei waters. One new species of the Apseudidae (in the genus Bunakenia) and four new species of the Parapseudidae (one each in the genera Platylicoa and Pakistanapeudes, and two in a new genus Actenos, of the subfamily Pakistanapseudinae) are described. The genus Platylicoa is moved to the Pakistanapseudinae, and the genus Hainanius is returned to the Parapseudidae (Parapseudinae). Apseudes tenuicorporeus is moved from Biropalostoma to the new pakistanapseudin genus described herein.
Subject(s)
Crustacea/classification , Animal Distribution , Animal Structures/anatomy & histology , Animals , Brunei , Crustacea/anatomy & histology , Ecosystem , Female , Male , Oceans and SeasABSTRACT
Following recent revelations regarding males with subchelate chelipeds in the tanaidacean genus Parakonarus, a number of Australian leptocheliid taxa are re-assessed, and their males and females variously re-allocated. To assist the interpretation of taxa with subchelate males, Heterotanais anomalus Sars is redescribed based on material from the Balearic Islands. The males of Konarus are now known to have a subchelate cheliped. The male (only) of Pseudoleptochelia bulbus from Melanesia is reassigned to Konarus cheiris, while Pseudoleptochelia bulbus sensu stricto is reassigned to Leptochelia together with its "minuta"-type male, as Leptochelia bulbus. Pseudoleptochelia straddi is rassigned to Konarus, together with its females from Queensland, Australia, which were previously assigned to Konarus cheiris. Pseudoleptocheliafairgo is confirmed as a member of Parakonarus, but material from Queensland is re-described as a new species. Other species previously assigned to Pseudoleptochelia are re-assessed: P. inermis, P. mercantilis and P. mortenseni sensu stricto are transferred to Leptochelia. The "small females" and males of P. mortenseni are transferred to Parakonarus as a new species. P. antarctica is provisionally reverted to Heterotanais, P. mergellinae to Leptochelia, and P. filum is tentatively transferred to Pseudonototanais. Pseudoleptochelia magna is synonymized with P. anomala. Pseudoleptochelia provincialis is tentatively transferred to Parakonarus. Pseudoleptochelia occiporta (females only) is reassigned to Leptochelia; the male of P. occiporta is considered to represent a species of Parakonarus. Pseudoleptocheliajuliae is reassigned to Parakonarus. Konarus, Makraleptochelia, Bassoleptochelia, Parakonarus and Pseudoleptochelia are placed in the new subfamily Konariinae. Generic relationships in this subfamily were confirmed by Principle Components Analysis. Catenarius is placed in the new subfamily Catenariinae.
Subject(s)
Crustacea/classification , Crustacea/genetics , Sympatry , Animal Distribution , Animal Structures/anatomy & histology , Animal Structures/growth & development , Animals , Australasia , Body Size , Crustacea/anatomy & histology , Crustacea/growth & development , Female , Male , Organ Size , PhylogenyABSTRACT
Three new genera, Acallocheirus, Aparatanais, and Penteparatanais, and seven new species of the paratanaid subfamily Paratanaidinae are described from New Zealand. New records of three previously known species Atemtanais taikaha, Paratanais paraoa, and P. tara, are also given. Paratanais denticulatus, P. intermedius, P. malignus, P. spinanotandus,and P. vicentetis are transferred to Aparatanais. A key is given to all paratanaidin genera and the NZ Paratanais species. In NZ waters, paratanaids are now known from the littoral zone to 908 m in the bathyal regions of the Chatham Rise and Hikurangi Margin, several of the offshore species being recorded in bryozoan mats. All but one appear to be endemic but may have sibling species elsewhere, particularly in the Southern Hemisphere. Supplementary notes are given on two Australian species P. maleficus and P. perturbatius that clarify their description and diagnostic characters.
Subject(s)
Crustacea/classification , Animal Distribution , Animal Structures/anatomy & histology , Animal Structures/growth & development , Animals , Body Size , Crustacea/anatomy & histology , Crustacea/growth & development , Ecosystem , Female , Male , New Zealand , Organ SizeABSTRACT
Examination of material housed at the Los Angeles County Museum of Natural History revealed a new species of Fageapseudes from 4100 m depth off California, the first record of the genus in the eastern North Pacific. Fageapseudes pluma n. sp. is very similar to the Japanese species Fageapseudes brachyomos Bamber, but can be distinguished by differences in setation and by having fewer articles in the antennal flagellum and uropodal exopodite. It is unique for the genus and subfamily in having the inner caudodistal seta of the maxillipedal endite "feather-like" instead of "leaf-like" or simply setulose. Problems with the current classification of the Apseudidae are briefly discussed, and new diagnoses are established for the subfamily Leviapseudinae and the genus Fageapseudes.
Subject(s)
Crustacea/anatomy & histology , Crustacea/classification , Animals , California , Female , Male , Pacific Ocean , Species SpecificityABSTRACT
Between 17th October and 9th November 2009, the third leg of the Chinese DY115-21 cruise on board the R/V Dayangyihao, confirmed two new hydrothermal fields near the equatorial East Pacific Rise. Five pycnogonid specimens were obtained by deep-sea TV-grab from one of the new hydrothermal vents named 'Precious Stone Mountain' at 1.22°N 101.49°W. These specimens belonged to two new species of the obligately-vent-associated pycnogonid genus Sericosura. Three female specimens represent the new species Sericosura gemmaenonsis with large body size. One male and one female were of the second new species, Sericosura dentatus; the male specimen has a mid-dorsal femoral cement-gland-tube, like that of Sericosura dissita, while the female specimen has more finely-denticulate spines on the oviger strigilis than any other species of the genus.
Subject(s)
Arthropods/anatomy & histology , Arthropods/classification , Hydrothermal Vents , Animal Distribution , Animals , Arthropods/physiology , Female , Male , Pacific Ocean , Species SpecificityABSTRACT
Leptocheliid material from sublittoral sandy substrata in the South China Sea off the coast of Brunei has been analyzed. Four species, all new to science, are described, all apparently interstitial in habitat. One is the second species to be described in the genus Catenarius (C. magdae); the others represent three new genera, one in each of the subfamilies Konariinae (Brunarus colekanus), Catenariinae (Ektraleptochelia phoxops) and Leptocheliinae (Nuberis areolaticola). As a result of the new information on the morphology of catenariins, the Andaman Sea species Leptochelia elongata is transferred to a new genus (Larsmentia) in the Catenariinae.
Subject(s)
Crustacea/classification , Animal Structures/anatomy & histology , Animal Structures/growth & development , Animals , Body Size , Brunei , Crustacea/anatomy & histology , Crustacea/growth & development , Ecosystem , Female , Male , Oceans and Seas , Organ SizeABSTRACT
Experiments have been undertaken exposing larval common shrimp (Crangon crangon) and lobster (Homarus gammarus) and adult copepods (Acartia tonsa) to the key stresses of entrainment within power-station cooling-water systems. The apparatus has enabled the testing of mechanical, thermal, chlorine and realistic pressure effects both alone and in combination, the range of stressors spanning the standard conditions found within a temperate coastal direct-cooled power station. Mechanical stresses affected only lobster larvae, pressure changes affected only the Acartia adults. Residual chlorine caused significant mortality of Acartia and shrimp larvae, but had no effect on lobster larvae even at 1 ppm. The temperature increment significantly affected all three species, with a synergistic effect on chlorine sensitivity in the shrimp larvae, but only temperatures higher than would be experienced in a normally-operating power station affected the copepods. The majority of individuals of each species would survive passage through a power-station system under normal conditions. It is notable that, within the species tested, generalizations from the responses of one species to those of another are not valid.
Subject(s)
Copepoda/physiology , Crangonidae/physiology , Nephropidae/physiology , Power Plants , Animals , Chlorine/toxicity , Copepoda/drug effects , Crangonidae/drug effects , Nephropidae/drug effects , Pressure , TemperatureABSTRACT
Performance assessment, impact detection, and the assessment of regulatory compliance are common scientific problems for the management of protected areas. Some habitats in protected areas, however, are rare and/or variable and are not often selected for study by ecologists because they preclude comparison with controls and high community variability makes meaningful change detection difficult. Shallow coastal saline lagoons are habitats that experience comparatively high levels of stress due to high physical variability. Lagoons are rare, declining habitats found in coastal regions throughout Europe (and elsewhere) where they are identified as one of the habitats most in need of protected area management. The infauna in the sediments of 25 lagoons were sampled. Temporal and spatial variation in three of these [protected] lagoons was investigated further over 5 years. In a multivariate analysis of community structure similarities were found between some lagoons, but in other cases communities were unique or specific to only two sites. The protected lagoons with these unique/specific communities showed significant temporal and spatial variation, yet none of the changes observed were attributed to human impacts and were interpreted as inherent variability. Multivariate control charts can operate without experimental controls and were used to assess community changes within the context of 'normal' lagoon variability. The aim of control chart analysis is to characterize background variability in a parameter and identify when a new observation deviates more than expected. In only 1 year was variability more than expected and corresponded with the coldest December in over 100 years. Multivariate control charts are likely to have wide application in the management of protected areas and other natural systems where variability and/or rarity preclude conventional analytical and experimental approaches but where assessments of condition, impact or regulatory compliance are nonetheless required.
ABSTRACT
Tanaidaceans are small peracarid crustaceans which occur in all marine habitats, over the full range of depths, and rarely into fresh waters. Yet they have no obligate dispersive phase in their life-cycle. Populations are thus inevitably isolated, and allopatric speciation and high regional diversity are inevitable; cosmopolitan distributions are considered to be unlikely or non-existent. Options for passive dispersion are discussed. Tanaidaceans appear to have first evolved in shallow waters, the region of greatest diversification of the Apseudomorpha and some tanaidomorph families, while in deeper waters the apseudomorphs have subsequently evolved two or three distinct phyletic lines. The Neotanaidomorpha has evolved separately and diversified globally in deep waters, and the Tanaidomorpha has undergone the greatest evolution, diversification and adaptation, to the point where some of the deep-water taxa are recolonizing shallow waters. Analysis of their geographic distribution shows some level of regional isolation, but suffers from inclusion of polyphyletic taxa and a general lack of data, particularly for deep waters. It is concluded that the diversity of the tanaidomorphs in deeper waters and in certain ocean regions remains to be discovered; that the smaller taxa are largely understudied; and that numerous cryptic species remain to be distinguished. Thus the number of species currently recognized is likely to be an order of magnitude too low, and globally the Tanaidacea potentially rival the Amphipoda and Isopoda in diversity.
Subject(s)
Crustacea/classification , Geography , Marine Biology , Animals , Biological Evolution , Ecosystem , Oceans and SeasABSTRACT
The construction of a new generation of coastal power stations in the UK and other western European countries has highlighted the absence of robust standards for thermal discharges to transitional and coastal waters. The proposed discharge volumes are greater than hitherto, yet there has been little independent critical examination of their potential impact, whilst much of the existing guidance has been adapted from freshwater practice. This review considers the available knowledge on the tolerance and behaviour of fish and other marine biota to heated effluents. Appropriate ways are suggested of grouping fish species to reflect their sensitivity to thermal effects. The plethora of existing standards are considered and their validity assessed in a framework of predicted seawater temperature rise. Those species or groups of organisms most likely to be affected are identified and finally specific recommendations for thermal standards consistent with long term sustainability are proposed.
Subject(s)
Aquatic Organisms/physiology , Hot Temperature/adverse effects , Seawater/chemistry , Water Quality/standards , Adaptation, Physiological , Animals , Fishes , Global WarmingABSTRACT
BACKGROUND: The question of how many marine species exist is important because it provides a metric for how much we do and do not know about life in the oceans. We have compiled the first register of the marine species of the world and used this baseline to estimate how many more species, partitioned among all major eukaryotic groups, may be discovered. RESULTS: There are â¼226,000 eukaryotic marine species described. More species were described in the past decade (â¼20,000) than in any previous one. The number of authors describing new species has been increasing at a faster rate than the number of new species described in the past six decades. We report that there are â¼170,000 synonyms, that 58,000-72,000 species are collected but not yet described, and that 482,000-741,000 more species have yet to be sampled. Molecular methods may add tens of thousands of cryptic species. Thus, there may be 0.7-1.0 million marine species. Past rates of description of new species indicate there may be 0.5 ± 0.2 million marine species. On average 37% (median 31%) of species in over 100 recent field studies around the world might be new to science. CONCLUSIONS: Currently, between one-third and two-thirds of marine species may be undescribed, and previous estimates of there being well over one million marine species appear highly unlikely. More species than ever before are being described annually by an increasing number of authors. If the current trend continues, most species will be discovered this century.