Troglocyclops janstocki,new genus,new species,a very primitive cyclopid (Copepods: Cyclopoida) from an anchialine cave in the Bahamas

Troglocyclops janstocki is proposed to accommodate cyclopids from Hatchet Bay Cave, Eleuthera Island, Bahamas. The species is the most primitive member of the Halicyclopinae because of the presence of 15-segmented antennules, mandibular palp reduced to 3 setae, one of them quite long and plumose, a bisegmented maxillary endopodite, and 3 segments in the maxilliped endopodite. These copepods possess the first pediger still distinct, being partially enclosed dorsally and laterally by a carapace-like extension of the posterior margin of the dorsal cephalic shield. This latter character represents a plesiomorphic state shared with the primitive cyclopinids and, within the Cyclopidae, only with the Euryteinae. The new taxon is the only known species of Halicyclopinae having two apical spines on the terminal segment of the exopodite of legs 2 to 4, and the intercoxal sclerites of the legs 1 and 2 sexually dimorphic. The phylogenetic importance of each of these characters is discussed.     

Three new genera and five new species of misophrioid copepods (Crustacea) from anchialine caves on Indo-West Pacific and North Atlantic Islands

Hydra lirosoma sp. nov. is a small, hermaphroditic species possessing broad holotrichous isorhiza nematocysts. The spherical embryo and cobbled embryotheca set it apart from similar species. Hydras with broad holotrichous isorhizas form a distinct cluster of species, but one which was not explicitly represented in the three genera ( Pelmatohydra, Hydra and Chlorohydra ) recognized by Schulze (1917, Archiv für Biontologie, 4(2 ): 29). Schulze failed to recognize this group because of the small number of species known at that time. The hydras that are known now fit naturally into four clusters of species termed, in this paper, the oligactis, vulgaris, viridissima, and braueri groups.     

Speleohvarella gamulini gen. et sp. nov., a new copepod (Calanoida, Stephidae) from an anchialine cave in the Adriatic Sea

A new copepod genus and species, Speleohvarella gamulini, collectedfrom the anchialine cave iva Voda on Hvar Island (Croatia),is described from both sexes. This is the first record of acalanoid copepod found in an Adriatic anchialine cave. The newgenus is distinguished from other Stephidae by a combinationof the following features: the cephalosome is separate fromthe first pedigerous somite, and the fourth and fifth pedigeroussomites are fused; the female urosome has 4 segments, the genitaldouble-somite is symmetrical and the caudal rami is asymmetricalwith the right longer than the left; antennules of both sexesare symmetrical and 24-segmented, with the fusion of ancestralsegments II–IV, X–XI and XXVII–XXVIII; theexopod of antenna is 7-segmented; 2 setae are present on thebasal exite of maxillule; in the male the right leg 5 is shortand 3-segmented, and the left leg elongate and 5-segmented.     

A polyphasic approach to the study of the genus Nitzschia (Bacillariophyta): three new planktonic species from the Adriatic Sea

The paraphyletic diatom genus Nitzschia comprises over 1000 morphologically distinct pennate taxa, known from the benthos and plankton of freshwater, brackish, and marine environments. The principal diagnostic characters for delimitation of Nitzschia species include valve shape, the position and structure of the raphe, presence/absence and shape of the proximal raphe endings and terminal raphe fissures, areola structure, and specific morphometric features such as cell size, and stria and fibula density. In this study, we isolated 12 diatom strains into culture from samples collected at the surface or greater depths of the southeastern Adriatic Sea. Morphological analyses included LM, SEM, and TEM observations, which, along with specific morphometric features, allowed us to distinguish three new Nitzschia species. These findings were congruent with the results of phylogenetic analyses performed on nuclear‐encoded SSU (18S) rDNA and chloroplast‐encoded rbcL and psbC genes. One of the new species (Nitzschia dalmatica sp. nov.) formed a lineage within a clade of Bacillariaceae containing members of the Nitzschia sect. Dubiae, which was sister to Psammodictyon. A second lineage was part of a novel clade that is significantly distinct from other Nitzschia species sequenced so far and includes Nitzschia adhaerens sp. nov. and N. cf. adhaerens. A further new species was found, Nitzschia inordinata sp. nov., which appeared as the sister group to the N. adhaerens clade and the conopeoid Nitzschia species in our phylogenetic trees. Our findings contribute to the overall diversity of genus Nitzschia, especially in identifying some deep branches within the Bacillariaceae, and highlight under‐scoring of this genus in marine plankton.     

Effects of food quality on growth and biochemical composition of a calanoid copepod,Argyrodiaptomus furcatus,and its importance as a natural food source for larvae of two tropical fishes

Growth, reproduction and biochemical composition were analyzed for the copepod Argyrodiaptomus furcatus fed on the alga Ankistrodesmus gracilis grown in different media. The ingestion of this copepod by larvae of two species of tropical fishes was also evaluated. The mean peak density of the copepod population was 1369 individuals l^–1 for all four diets used, and the highest was 1387 individuals l^–1 on diet ARV (algae + ration + vitamins). A small copepod, A. furcatus tends to have a short life span. The smallest females did not attain maturity in the shortest time on all diets used. Food quality may play a major role in the dynamics of the biochemical composition of this copepod. Argyrodiaptomus furcatus was a more important food item for larvae of tambaqui (Colossoma macropomum) than of pacu (Piaractus mesopotamicus). However, it made up a large part of the gut contents of larvae of both species.     

Mospicalanus schielae,a new genus and species of calanoid copepod (Crustacea: Spinocalanidae) from deep Antarctic water

A new genus and species,Mospicalanus schielae, collected at bathypelagic depth in the Antarctic Ocean, is described from female specimens and a stage V male. The new species is placed in the Spinecalanidae on account of the absence of fifth legs and leg 1 characteristics. It appears to be closely related toMimocalanus Farran. 1908, sharing apomorphic characters such as the lack of a rostrum, reductions of setal armament on the mouthparts, and absence of an outer spine on the first exopod segment of leg 1.Mospicalanus schielae can be distinguished from other spinocalanid genera by the setation of the antennary exopod, the maxillule, and the paecoxal endite of maxilla. Diagnostic characters of Spinocalanidae and Bathypontiidae are also discussed in order to clarify affiliation of genera tentatively assigned to the latter family. An updated key is given for the spinocalanid genera.     

A new species of Phyllodiaptomus Kiefer (Copepoda,Calanoida) from South India

Phyllodiaptomus sasikumari, a new species of calanoid copepod is described from the material collected in several ephemeral ponds and pools in the Palghat District of Kerala State, South India.     

New stygobiont copepods (Calanoida; Misophrioida) from Bundera Sinkhole, an anchialine cenote in north-western Australia

Two new taxa in the copepod orders Calanoida and Misophrioida are described from the flooded coastal karst of north-western Australia. Stygocyclopia australis sp. nov. is the first pseudocyclopiid calanoid to be reported from the continent, with other congeners distributed in anchialine environments of the Philippine, Balearic, and Canary archipelagos. The presence of a supernumerary spine on the outer margin of the first exopod segment of leg 3 in this species is discussed in the context of the Neocopepodan groundpattern. Speleophria bunderae sp. nov. is the first representative of the order Misophrioida known from Australia, with other congeners in the Balearics, Bermuda, and the Yucatan peninsula of México. Both taxa co-exist in the deeper higher salinity layers of a single sinkhole in Cape Range peninsula. The placement of these taxa in strictly stygobiont genera represented by very localized and disjunct species distributed over regions flooded by the late Mesozoic seas, lends support to their interpretation as true Tethyan relicts, and hence to the inclusion in the past of the Northwest portion of Australia in the Tethyan realm. The remains of S. bunderae in the gut contents of a stygobiont epacteriscid calanoid is recorded.     

Diel vertical migration and gut pigment rhythm of Paracalanus parvus,P. crassirostris,Acartia erythraea and Eucalanus subcrassus (Copepoda,Calanoida) in Tolo Harbour,Hong Kong

Diel vertical migration and gut pigment rhythm of calanoid copepods were studied in the highly eutrophic waters of Tolo Harbour, Hong Kong in summer between July 30 and August l, 1991 and in winter between January 24 and 25, 1992. Paracalanus parvus and P. crassirostris showed neither diel vertical migration nor diel gut pigment rhythm during the summer study. Acartia erythraea and Eucalanus subcrassus exhibited prominent diel vertical migration and diel gut pigment rhythm. Diel changes in gut pigment content of surface dwelling individuals and increase of gut pigment content before the onset of nocturnal upward migration suggest that gut pigment rhythm in E. subcrassus was not the result of animals moving in and out of a food-rich surface layer. During the winter study, the harbour was affected by a bloom of Noctiluca scintillans. P. parvus and P. crassirostris resided in deeper waters presumably to avoid the dense populations of N. scintillans at the surface. P. crassirostris remained non-migratory during the winter study. There was a nocturnal increase in the number of P. parvus in the surface waters, although no diel change in the mean depth of the population was observed. Both Paracalanus species showed diel gut pigment rhythm. The presence of diel gut pigment rhythm in the non-migratory P. crassirostris during the winter study suggested the presence of an independent feeding rhythm.     

A new genus and species of cyclopoid (Crustacea,Copepoda, Cyclopinidae) from a coastal system in the Gulf of Mexico

A new, monotypic genus of the interstitial marine cyclopoid copepod family Cyclopinidae G.O. Sars, 1913 is described from male and female specimens collected at Laguna de Términos, a large coastal lagoon system in the southern Gulf of Mexico. Mexiclopina campechana gen. et sp. n. cannot be adequately placed in any extant genus within the family. It differs from other cyclopinid genera in having a unique combination of characters including: 1) absence of modified brush-like seta on the mandibular exopod; 2) maxillule exopod with stout setal elements and brush-like setae absent; 3) basis of mandible with one seta; 4) presence of a modified seta on endopod of fourth leg; 5) fifth leg exopod unsegmented, armed with three elements in the female and five in the male; 6) intercoxal sclerite of first swimming leg with two medial spiniform processes on distal margin. The new genus is monotypic and appears to be most closely related to Cyclopina Claus, 1863 and Heptnerina Ivanenko & Defaye, 2004; the new species was compared with species of Cyclopina and it resembles Cyclopina americana Herbst, 1982 and Cyclopina caissara Lotufo, 1994. This is the second record of a species of Cyclopinidae in Mexico and the first in the Gulf of Mexico; the number of cyclopinid species recorded from the Americas is now 13.     

A new species of Peltidium Philippi, 1839 (Crustacea,Copepoda, Harpacticoida) from the Pacific coast of Mexico

During the analysis of phytal meiobenthic samples collected from a rocky-sandy beach in the state of Nayarit, in the Mexican Pacific, several specimens of harpacticoid copepods were obtained and taxonomically examined. These specimens were found to represent an undescribed species of the peltidiid genus Peltidium Philippi, 1839. The new species, Peltidium nayarit sp. n. is described herein. It resembles Peltidium nichollsi Geddes and Peltidium lerneri Geddes from Bahamas but also the widespread Peltidium speciosum Thompson & Scott and Peltidium purpureum Philippi. The new species from the Mexican Pacific differs from its known congeners by its possession of a unique combination of characters, including a modified pectinate seta on the antennary exopod, three terminal setae on the second endopodal segment of leg 1, third exopodal segment of leg 1 with three elements, inner terminal claw twice as long as outer claw, female fifth leg with 5 exopodal setae, exopodal setae I-III stout, spinulose and seta IV being as long as seta V. This is the second species of the family known to be distributed in the Eastern Tropical Pacific and in Mexico. Pending additional data, the distribution of this species appears to be restricted to this area of the Mexican Pacific.     

First record of the Sphyraena chrysotaenia (Klunzinger, 1884) (Pisces, Sphyraenidae) from the Adriatic Sea

One specimen of the obtuse barracuda Sphyraena chrysotaenia is recorded for the first time from the Adriatic Sea.     

Revision of basal calanoid copepod families,with a description of a new species and genus of Pseudocyclopidae

A newly discovered plesiomorphic genus and species of calanoid copepod ( P inkertonius ambiguus gen. et sp. nov. ) taken with an epibenthic sledge from the flanks of the Chatham Rise, east of New Zealand, at a depth of about 900 m, could not be assigned to any known genus or family based on available diagnoses. A morphology‐based cladistic analysis of all genera previously placed in the Epacteriscidae, Pseudocyclopidae, Ridgewayiidae, Boholinidae, and the new taxon is presented. The Pseudocyclopidae and Epacteriscidae are confirmed as monophyletic families, and the family names Ridgewayiidae and Boholinidae become synonyms of Pseudocyclopidae. There are no grounds upon which more than a single basal superfamily, the Pseudocyclopoidea, can be recognized. The superfamily Pseudocyclopoidea, and families Pseudocyclopidae, Epacteriscidae, and the new genus are diagnosed. P inkertonius ambiguus gen. et sp. nov. is placed within the Pseudocyclopidae. Genetic data adds to the definition of the new taxon and confirms the basal position of the Pseudocyclopoidea in a revised Calanoida phylogeny. This phylogeny contributes to an improved resolution of the relationships among the Centropagoidea, Megacalanoidea, Bathypontioidea, Eucalanoidea, and Clausocalanoidea, as well as providing testable hypotheses for future work. © 2014 The Linnean Society of London     

Ecological and morphological characteristics of Ephelota gemmipara (Ciliophora,Suctoria), epibiontic on Eudendrium racemosum (Cnidaria,Hydrozoa) from the Adriatic Sea

The relationship between the suctorian Ephelota gemmipara and the large hydroid Eudendrium racemosum from the North Adriatic Sea has been studied over its full annual cycle. Ephelota gemmipara settles on the perisarc of the hydroid, usually close to the hydranths in order to exploit the hydroid's food discharges. The life cycle of E. gemmipara is influenced by temperature variations and by its relationship with the host. The hydroid shows an active phase in the summer, and it gets through the adverse winter season forming resting stages. In April, when temperature increases, the hydroid starts its active phase and it is colonized by suctorians. From May to September the suctorians produce multiple buds (swarmers) that detach from the parental cells to settle on an Eudendrium colony. The abundance of the suctorian peaks in September, with more than 1.2 million ind. m^?2. Their proliferation coincides with the maximal abundance of their host and the highest water temperatures. On the contrary, sexual reproduction and the encystment occur when the temperature and the abundance of E. racemosum decrease. Lastly, we also report the presence of symbionts such as bacteria and the parasitic protozoans Tachyblaston ephelotensis and Enigmocoma acinetarum.     

Hadodiaptomus dumonti n. gen., n. sp., a new freshwater stygobitic calanoid (Crustacea: Copepoda: Calanoida) from Vietnam (South Asia) and a new member of the subfamily Speodiaptominae Borutzky, 1962

A new species of freshwater stygobitic calanoid, Hadodiaptomus dumonti n. gen., n. sp., from a cave in Vietnam (South Asia) is described. It is the ninth taxon from the order Calanoida described from freshwater subterranean (i.e. cave) environments. It is the fourth member of the subfamily Speodiaptominae Borutzky, 1962. It differs from stygobitic taxa in Europe and Mexico by numerous characters, especially in the armature of P1–P5, antenullas, mouth parts and genital segments in both sexes. Arthrodial membrane development from CII to CV is different from epigean as well as from subterranean taxa. These differences suffice to raise a new genus–Hadodiaptomus, characterised by two-segmented exopodites and endopodites of P1–P4 and reduced P5 endopodites in both sexes. Males are without widened segments 13–18 on right A1. Relations with other stygobitic taxa of the subfamily Speodiaptominae are discussed.     

A new Stygonitocrella Petkovski (Copepoda: Harpacticoida) from a cave in Northern Mexico with comments on the taxonomy of the genus

The cave-dwelling harpacticoid copepod fauna of Mexico is still yet to be known. There are only a few records related to karstic caves, but most refer to epigean forms. The analysis of samples collected in a cave system in Northern Mexico yielded two female specimens of an unknown harpacticoid copepod species which is described herein. It was assigned to the genus Stygonitocrella Petkovski, 1976 mainly because of the presence of a single endopodal segment on legs 1–4; the new species, S. mexicana n. sp. differs from its congeners by a combination of characters related to the segmentation and armature of the swimming legs 1–4, the fifth leg of the female, and the strcture of the antennae. Based on the current limits of Stygonitocrella, two new subgenera are proposed to recognize different morphological patterns based on the presence or absence of an inner baseoendopodal lobe in the female fifth leg, a character not evaluated before. This lobe is absent in the new species and in other five species now contained in the subgenus Eustygonitocrella. A lobe is present in the new subgenus Fiersiella, also with six species. This is the second record of Stygonitocrella in North America, after S. (Fiersiella) sequoyahi Reid, Hunt & Stanley, 2003; it is the only North American cave-dwelling species of the genus. It is suggested that the influence of marine transgressions in Northern Mexico was related to the origin of the new species as part of a group of troglobitic forms originated from marine interstitial ancestors that colonized the freshwater caves. A key for the identification of all the known species of Stygonitocrellais also provided.     

Selective feeding of Arctodiaptomus salinus (Copepoda, Calanoida) on co-occurring sibling rotifer species

1. Using two‐ and three‐dimensional video recordings, we examined the steps involved in predation that lead to the differential vulnerability of three sympatric rotifer sibling species (Brachionus plicatilis, B. ibericus and B. rotundiformis) to a co‐occurring, predatory, calanoid copepod (Arctodiaptomus salinus). 2. Brachionus rotundiformis, the smallest prey tested, was the most vulnerable with the highest encounter rate, probability of attack, capture and ingestion, and the lowest handling time. 3. Comparison of our results with those of a previous study shows that A. salinus is a more efficient predator than a co‐occurring cyclopoid copepod (Diacyclops bicuspidatus odessanus) feeding on these same rotifer species. However, despite its higher capture rates, A. salinus seems to be less selective than D. b. odessanus based on attack distances and prey handling times. 4. The differential vulnerability to both calanoid and cyclopoid copepod predation can help explain the coexistence and seasonal succession of these co‐occurring rotifer species.