Segment Of Antenna Research Articles

A new species of the genus Porirualia Huys & Mu, 2021 (Copepoda, Harpacticoida, Parastenheliidae) from the intertidal zone of Qingdao, China, with a key to species of the genus

A new species belonging to the genus Porirualia Huys & Mu, 2021 was identified and described here based on samples collected from No. 1 Bathing Beach, Qingdao, China. The new species differs from Porirualia pyriformis mainly in the following characteristics: P3 and P4 exp-3 with three inner setae (two inner setae in P. pyriformis), ratio of length to maximum width of female P5 3.83 (3.25 in P. pyriformis). The new species differs from Porirualia megarostrum by the characters including rostrum reaching to distal margin of third segment of antennule (reaching to distal margin of fifth segment of antennule in P. megarostrum), ratio of length to maximum width of female P5 3.83 (2.2 in P. megarostrum); male P2 and P3 two-segmented (three-segmented in P. megarostrum); male P5 bearing five elements (six in P. megarostrum). This is the first report of the genus Porirualia from the China Seas. The DNA barcode (COI) sequence of the new species was obtained and submitted to GenBank (PP761118), which is the first submission of COI sequence of the family Parastenheliidae to GenBank.

External morphology of newly-hatched juveniles of Aegla lata (Crustacea, Aeglidae)

ABSTRACT Aegla is a genus of freshwater anomuran Crustacea known for having epimorphic postembryonic development. The newly-hatched juveniles’ morphology have been described for only 11 of the 93 known species. These descriptions are important tools for identifying juveniles and useful characteristics for phylogenetic analyses. This study aims to describe and illustrate the external morphology of the first juvenile stage of Aegla lata. Ovigerous females were collected, fed, and monitored periodically in the laboratory until the eggs hatched. The newly-hatched juveniles were fixed in an alcohol series and preserved in a 70% alcohol and glycerine solution (2:1 ratio) for subsequent dissection and analysis under light microscopy. The appendages were illustrated using a camera lucida and then described. Scanning electron microscopy was used to analyse some specimens, allowing the detailed observation of the setal morphology, some cephalothoracic appendages, and lineae aeglicae. Pappose setae were also observed in the protopod and dactylus of cheliped. The newly-hatched juvenile of A. lata has a set of the following characteristics: basal segment of antennule with serrate setae; distal segment of antennule with pappose setae; merus of second maxilliped with simple setae; and merus of third maxilliped without simple setae.

Two new species of Cerviniella Smirnov, 1946 (Copepoda, Harpacticoida, Aegisthidae) from the Yellow Sea, Korea.

Two new species, Cerviniellabisegmentasp. nov. and C.permixtasp. nov., are described in detail with illustrations based on females from the Korean Yellow Sea. These species lacking the fourth leg endopod belong to the mirabilipes group, one of two species groups within the genus Cerviniella Smirnov, 1946. Both species can be distinguished from each other by the surface ornamentation of the cephalothorax, shape of the rostrum tip, antennule segments, armature formula of thoracic legs 1-4, and length ratio of the caudal rami. Cerviniellabisegmentasp. nov. is characterized by a short caudal ramus and a two-segmented antennary exopod, which are unique within the genus. Cerviniellapermixtasp. nov. differs from other congeners of the mirabilipes group by the seven-segmented antennule, the armature formulae of the exopod of the antenna and thoracic legs 1-4, and the modified apical inner element of the second endopodal segment of the second leg. The present study is the first to identify the genus Cerviniella in Korean waters, resulting in extension of its distribution area to East Asia.

Mastigodiaptomus galapagoensis n. sp. (Crustacea: Copepoda: Diaptomidae), a possibly extinct copepod from a crater lake of the Galápagos archipelago.

A new species of a Neotropical diaptomid copepod is described based on individuals recovered from a small, almost forgotten collection of unique plankton samples from El Junco, a crater lake in San Cristóbal island, Galápagos archipelago. This copepod was regularly reported (1966-2004) as an abundant zooplankter in the lake, but it was not found in subsequent plankton surveys (2007-2018), and its specific identity remained unknown. In 2020, it was declared extinct because of introduced fish predation, rotenone treatment, and other major disturbances. The taxonomic examination of these invaluable specimens allowed us to recognize them as representing an undescribed species of the freshwater diaptomid genus Mastigodiaptomus Light, 1939. Here, we describe the new species from El Junco crater lake, located in the San Cristóbal island a part of the Galápagos archipelago, collected with plankton nets. The description is based on detailed morphology, based on SEM and light microscopy. The taxonomic examination of these invaluable specimens allowed us to recognize them as representing an undescribed species of the freshwater diaptomid genus Mastigodiaptomus Light, 1939. The new species was readily assigned to this genus and is distinguished from its known congeners by details of (1) the male right fifth leg terminal claw and aculeus, (2) spiniform processes pattern of the right geniculate antennule segments 10-16, (3) length and structure of the spiniform process of the antepenultimate segment of the male right antennule, and (4) details of the dorsal process on the female fourth pediger. This finding represents the first report of this Neotropical copepod genus outside its original biogeographic region, the third species of a diaptomid copepod reported from insular freshwater systems, the southernmost record of Mastigodiaptomus, and the only freshwater calanoid in the Galápagos. The intriguing presence of this chiefly Neotropical copepod genus here could be related either to (1) human agency linked to pirate activities, commercial travelling by Spaniard ships, whaling activities, and intense tortoise hunting in San Cristóbal island. In the past, El Junco was the only freshwater source 600 nautical miles around, or (2) zoochory of resistant dormant stages passively transported by more than 65 migrating bird species known to settle in San Cristóbal. These two hypotheses cannot be properly tested at this time, so the explanation of the presence of this copepod will remain as a new open question in the fascinating natural history of the Galápagos.

Two new species of Cymbasoma (Multicrustacea: Copepoda: Monstrilloida: Monstrillidae) from the North Atlantic

ABSTRACT Monstrilloid copepods are protelean endoparasites of benthic invertebrates. Their adult free-living stage is chiefly found in the plankton of shallow coastal systems, estuaries and coral reefs; there are no previous records of monstrilloids from deeper marine habitats including epipelagic or mesopelagic waters. Two new species of the monstrilloid copepod genus Cymbasoma Thompson, 1888 are described based on adult females incidentally captured by an epibenthic sledge operated at a depth range of 118–302 m off north-west Iceland and the Norway Channel. Cymbasoma norvegicum sp. nov. is distinguished by a combination of characters including a long, constricted anal somite, bilobed fifth legs with long inner lobe, antennules with fused segments, and first antennule segment unarmed. Cymbasoma pedroi sp. nov. has a pair of rounded posterolateral protuberances on the genital somite, fused fifth legs lobes, and an anteriorly produced, ornamented forehead. Both species are considered new members of the Cymbasoma rigidum species group, widely distributed in different geographic areas but not previously known from epi-mesopelagic depths. The finding of these new species represents the first discovery of monstrilloids at epi-mesopelagic depths in the Pacific Ocean and it significantly adds to our knowledge of this copepod order, thus highlighting their potentially high yet unstudied diversity in deeper waters. http://www.zoobank.org/urn:lsid:zoobank.org:pub:C05EEC28-9936-41CB-BC9E-D990AE53B3B1

A new species of Nitokra Boeck, 1865 (Copepoda, Harpacticoida, Ameiridae) from the Caribbean coast of Colombia.

Biological samples obtained from a coastal system of northern Colombia yielded male and female specimens of an undescribed harpacticoid copepod of the diverse ameirid genus Nitokra Boeck, 1865. The new species is a member of the genus group III. We describe the new species based on adult male and female individuals. Nitokrapuebloviejensis sp. nov., appears to be most closely related to N.vietnamensis Tran & Chang, 2012, but they can be separated by the following characters: 1) number of setal elements on second segment of mandibular palp, 2) P1ENP/EXP ratio, 3) relative lengths of P2, P3ENP/EXP, 4) number of elements on male P5EXP and ENP, and 5) segmentation of male antennule. In addition, N.puebloviejensis sp. nov. can be confused with two other congeners: N.taylori Gómez, Carrasco & Morales-Serna, 2012 from South Africa and Colombia and N.kastjanensis Kornev & Chertoprud, 2008 from the White Sea, but the new species can be distinguished from them by: 1) number of setae on the maxillule coxa, 2) P1ENP/EXP ratio, 3) P2,P3ENP/EXP ratio, 4) female and male P5 setophore, 5) setation pattern of female P5EXP and ENP, 6) structure of female P6, 7) ornamentation of female anal operculum, 8) number of setae on male P5EXP, and 9) the male antennule segmentation. Most importantly, the presence of a group of five short setae on the medial surface of the maxilliped syncoxa allows the new species to be readily distinguished from its congeners. Only two subspecies and one species of this genus have been hitherto recorded from Colombia. A key to the 23 known American species of Nitokra is provided.

A New Species of Hatschekiid Copepod (Crustacea: Hatschekiidae) Parasitic on the Porkfish Anisotremus virginicus (Linnaeus, 1758) (Actinopterygii: Haemulidae), with Notes on Previously Known Species of Hatschekia Poche, 1902 Collected from Actinopterygians off Brazil.

Copepods of the genus Hatschekia Poche, 1902 are parasitic on the gills of marine actinopterygians. Currently, about 151 species of this genus have been reported in marine ecosystems and only few occur in South Atlantic Ocean. Fifty specimens of A. virginicus from Angra dos Reis, off the State of Rio de Janeiro, Brazil, were parasitized by copepods on the gills. Parasites were fixed and preserved in 70% ethanol. Morphological observations were based on light and scanning electron microscopy. Hatschekia nagasawai n. sp. can be distinguished from all congeners by the combination of the following characters: (1) presence of two pointed processes on the proximal (first) segment of antennule, (2) cephalothorax octagonal to ovoid, (3) absence of processes on the intercoxal sclerite of legs 1 and 2, (4) trunk without lobes at the postero-lateral margins. Other species of Hatschekia and their hosts previously collected off Brazil were analysed and discussed. This is the first report of a representative of the family Hatschekiidae Kabata, 1979 parasitizing a species of Anisotremus. The number of species of Hatschekia reported in the South Atlantic Ocean was increased to five, including the new species; however, the diversity of hatschekiid copepods in this oceanographic region is still underestimated, most likely being higher than what is currently known.

A new species of Esola Edwards, 1891 (Crustacea, Copepoda, Harpacticoida, Laophontidae) from the Caribbean coast of Colombia.

A new species of the harpacticoid copepod genus Esola is described from specimens collected in Rodadero Beach, on Gaira Bay, on the Caribbean coast of Colombia. The species, E.wellsisp. nov., is described, illustrated, and com­pared with its congeners. Esolawellsisp. nov. differs from its known congeners in details of the armature of legs 1–4. It most closely resembles E.bulbifera (Norman, 1911) in the armature formula of P1–P5 but differs from the latter in several respects, including the female antennule segmentation (7-segmented in E.bulbifera but distinctly 6-segmented in E.wellsisp. nov.) and in the shape and size of the male P3ENP2 apophysis, among other characters. This is the second species of the genus known from the Caribbean and the second record of Esola in the Northwestern Tropical Atlantic. The genus now contains eight species. A key to the known species of the genus is also included.

Proposal of Arktourella gen. nov., a new genus of the family Normanellidae Lang 1944 (Copepoda: Harpacticoida) from the Province of Cortez.

A new genus, Arktourella gen. nov., is proposed to accommodate a new member of the harpacticoid family Normanellidae, A. margarethae gen. et sp. nov., from a polluted estuary in north-western Mexico. The new genus was attributed to the laophontoidean family Normanellidae on account of the lack of outer spinous processes on the second antennulary segment, one abexopodal seta on the antennary allobasis, four setae on the one-segmented antennary exopod, endopod of first swimming leg two-segmented with first segment elongated and with two distal elements on second segment, endopods of second to fourth legs two-segmented, distal setae on the male second endopodal segment of second and third legs reduced, and outer spine of the male second endopodal segment of third leg fused to segment. The new, so far monotypic genus, differs from the other normanellid genera in the presence of four elements on the third exopodal segment of the first leg, and two outer spines on the third exopodal segment of second to fourth legs. No synapomorphies were observed for Arktourella gen. nov. and Normanella, but they are unique within the Normanellidae in that the mandibular basis and endopod are not fused. Maximum parsimony analysis and Bayesian inference using 59 morphological characters to assess the relationships between the genera of the family Normanellidae confirmed the affinity of Arktourella gen. nov. and Normanella, and their sister group relationship with Sagamiella. Paranaiara and Pseudocletodes were shown consistently to be closely related and are the sister taxa of Normanella-Arktourella gen. nov.-Sagamiella. Arktourella gen. nov., Paranaiara and Pseudocletodes share the presence of a large spinulose spine on the fifth and sixth segments of the female antennule, but its significance is not clear. Additionally, we propose a key to the genera of the Normanellidae.

Description of three new species of Bradyidius (Copepoda: Calanoida), the new aetideids from the deep Pacific Ocean, with notes on the genera Bradyidius and Aetideopsis.

Three new aetideid species, Bradyidius abyssalis sp. nov., Bradyidius parabyssalis sp. nov., and B. kurilokamchaticus sp. nov. are described from female specimens collected near the seafloor in the abyss of the Pacific and Atlantic Oceans. Specimens of Bradyidius parabyssalis sp. nov. were obtained in both the Atlantic and Pacific Oceans (Argentine Basin, area of the Meteor Seamount and the Kurile-Kamchatka Trench). Bradyidius abyssalis sp. nov. was found only in the Atlantic Ocean, (Brazil and Guinea Basins and area of the Meteor Seamount) and Bradyidius kurilokamchaticus sp. nov. was recorded from the Kurile-Kamchatka Trench of the Pacific Ocean. Three new herein described Bradyidius species constitute the first documented records of the genus from the abyss of the World Ocean. In addition, three Bradyidius species from the Weddell Sea, the Atlantic Ocean and the Kurile-Kamchatka Trench, are briefly described without biological names due to their bad condition. Bradyidius parabyssalis sp. nov. and B. abyssalis sp. nov. are distinguished from all known congeners by the presence of 3 setae at the basis of the mandible and morphological details of the prosome posterior corners and P1. They show close resemblance to each other but differ in body size, rostrum structure, P4 coxa armament and length of the setae of the antennule ancestral segment I and the mandible basis. Bradyidius kurilokamchaticus sp. nov. shares with B. curtus Markhaseva, 1993, B. pacificus (Brodsky, 1950) and B. arnoldi Fleminger, 1957 a rostrum with non-divergent or parallel points, but differs from these species in the size, the well developed lateral spine on exopod segment 1, in the number of setae at the antenna exopod segment 1 and some morphological details of the prosome posterior corners. Characters that define the genus Bradyidius Giesbrecht, 1897 from Aetideopsis Sars, 1903, i.e. the shape of lateral spines of P1exopod segments 1 and 2; the endopod of P2 segmentation and the setation of the antennule ancestral segments XII, XV and XVII are discussed.

Pseudoneotachidius sinuspersici gen. et sp. nov., a new member of the family Tachidiidae Boeck, 1865 (Copepoda: Harpacticoida) from Iran

A new member of the harpacticoid copepod family Tachidiidae Boeck, 1865 was found in sediment samples of meiobenthic harpacticoids taken during a study on the diversity of meiobenthic harpacticoids along the northern coast of the Persian Gulf. The taxonomic analysis of this material revealed that it contained an undescribed species. A new genus is herein proposed to accommodate the new species. The new genus, Pseudoneotachidius gen. nov., displays superficial similarities with Neotachidius Shen & Tai, 1963 and Cithadius Bowman, 1972, and a closer relationship is hypothesized with the former. The lack of a midventral copulatory pore, the female P5 endopodal lobe with two inner spines, and P1 with one inner seta on enp-3 are regarded here as synapomorphies for both Neothachidius and Pseudoneotachidius gen. nov. These two genera can be separated by several characters, including the structure and shape of the male fourth antennulary segment, segmentation of the antennary exopod, ornamentation of the male P2 enp-3, sexual dimorphism of the male P2 enp-2, structure and shape of the male P5, morphology of the male P2 and P3, male and female P5 armature complement and ornamentation, male P6, ventral spinulation pattern of the female genital-double somite, and in the mouthparts armature of among others. An updated key to the genera of the family Tachidiidae is presented.

Two new species of Cryptopontius Giesbrecht, 1899 (Copepoda, Siphonostomatoida, Artotrogidae) associated with invertebrates from Northeastern Brazil.

Cryptopontius is the most species-rich genus in the family Artotrogidae with 25 species, being recorded in almost all oceans, except in the Arctic. However only three species of this genus have been recorded from the Brazilian coast, all of them along the coast of Pernambuco state. This study describes two new species of the genus. Cryptopontius phyllogorgius sp. nov. differs from other species by having 9-segmented antennule, and nine elements on the third exopodal segment of leg 4. Cryptopontius pentadikos sp. nov. differs from its congeners by having five expressed antennulary segments proximal to fused ancestral IX-XII, two setae on second endopodal segment of leg 1, eight elements on third exopodal segment of leg 1 and the free segment of leg 5 with two setae. A key to species of the genus Cryptopontius is provided.

Description of two deep-water copepods of the genus Leptotachidia Becker from the northwestern Pacific (Harpacticoida, Pseudotachidiidae).

The monospecific genus Leptotachidia Becker, 1974 (Pseudotachidiidae Lang, 1936) was previously known only from the deep Atlantic. Female specimens of two unknown species of this genus were collected from abyssal sediments during an expedition to the northwestern Pacific on board research vessel ISABU (Korea Institute of Ocean Science and Technology) in November 2017. In this paper we describe the females of two new species, L. senariasp. nov. and L. apousiasp. nov. The new species were attributed to the genus Leptotachidia by the combination of the five-segmented female antennule, presence of the Brodskaya organ on the distal antennulary segment, and the second exopodal segments of second to fourth legs without inner setae. An outstanding character of both Pacific species is the reduced armature of thoracic legs in contrast to the type species, L. iberica Becker, 1974. In addition, the setal armature of L. senariasp. nov. and L. apousiasp. nov. is unique within the genus in that the female leg 5 of L. senariasp. nov. has six elements instead of five; and the antennary exopod of L. apousiasp. nov. bears a single seta on the proximal segment instead of two. This is the first record of Leptotachidia from the Pacific. A key to all three species of Leptotachidia is provided.

Redescription and Relationships of Eucyclops persistens (Copepoda: Cyclopidae) Endemic to the Azov-Black Sea Basin

The cyclopoids of the Ponto-Caspian region has been discussed in numerous articles and seminal monographs of the late V. I. Monchenko, yet relationships of this peculiar fauna to other regions are still poorly understood. Two subspecies of Eucyclops persistens known from interstitial waters in the Black sea region are redescribed here, based on the type material. Eucyclops persistens persistens (estuary zone of Caucasian rivers) and E. persistens tauricus (wells in Crimea) differ from each other in the lateral surface ornamentation of the caudal rami in female (naked, vs. short serra present), and the relative length of the dorsal caudal seta in both female and male (seta longer in E. persistens tauricus). Eucyclops persistens s.l. share some characters, such as the reduced “serra”on the caudal rami, reduced lateral pilosity of pediger 5, lack of (or few) hairs on the distal margin of P4 intercoxal sclerite, and long aesthetasc on the ninth antennulary segment in female, with some European subterranean taxa in the Eucyclops graeteri complex. Sparse morphological information on the graeteri-complex hinders a rigorous phylogenetic analysis. Future revision of the graeteri-complex might shed light on a Western/Central Europe – Ponto-Caspian connection during the evolution of these subterranean Eucyclops.

Two new species of parasitic copepods from the genera Nothobomolochus and Unicolax (Cyclopoida: Bomolochidae) from Australian waters.

A 2016 collaborative survey of commercial fish parasites in Moreton Bay, Queensland, Australia led to the discovery of two new species of parasitic copepods belonging to the family Bomolochidae. Females of Nothobomolochus johndaveorum n. sp. were found attached to the gill filaments of Gerres subfasciatus and Gerres oyena. The new species most closely resembles N. leiognathicola and N. quadriceros. All 3 species possess 3 modified setae on the first antennulary segment that are approximately the same length and have a robust seta on the second antennulary segment adjacent to the 3 modified setae giving a superficial appearance of 4 modified setae on the antennule. The new species can be distinguished from these two species in its possession of longer inner setae on the first two endopodal segments of leg 4: the seta on endopodal segment 1 extends past the midline of the distal segment in the new species vs to the proximal margin of the distal segment in the other two species, and the seta on segment 2 extends well beyond the distal margin of the endopod in the new species vs just to the margin in the other two species. Females and males of Unicolax longicrus n. sp. were found in the nasal sinuses of Sillago maculata and Sillago ciliata. The new species differs from 6 of its 7 congeners in having a leg 4 exopod formula of II, I, 4 rather than II, I, 3 or II, I, 5. The new species resembles U. anonymous in this feature, but differs in its possession of a leg 5 that is relatively longer and less wide, and, whereas U. anonymous possesses inner and outer distal spines on leg 5 that are approximately the same length, those of the new species are relatively longer and asymmetrical. Unicolax longicrus n. sp. is unique among its congeners in its possession of a leg 4 with highly elongated endopodal segments 2 and 3, from which its name is derived. In addition to describing the two new species, host and locality reports for all species of Nothobomolochus and Unicolax are reviewed.

Two new species of Diarthrodes (Copepoda: Harpacticoida: Dactylopusiidae) from the Caribbean coast of Colombia

Biological samples obtained from a coastal system of northern Colombia yielded the first record of the harpacticoid copepod genus Diarthrodes Thomson, 1883 for Colombia by the presence of 2 new species. We describe the new species based on male and female specimens. Diarthrodes bodini sp. nov., a member of group I (sensu Gómez et al., 2008), appears to be most closely related to D. latisetosus Chislenko, 1978 but differs in the ornamentation of the urosomites, the length/width ratio of the P1 ENP, the relative length of the inner spine of P1 ENP1, the relative length of P3 and P4 ENP, details of the female P5 armature and seminal receptacle, and details of the male P2ENP2 and antennule segmentation. The second species, D. gomezi sp. nov. belongs to group IV; it is unique among related congeners in possessing 7 setal elements on P3-P4EXP3. It resembles D. minutus (Claus, 1863) but diverges in therelative length of the inner seta of P1ENP1, the armature of the female P1EXP2 and P5, the structure of the modified male P2ENP2, and the armature of the male P5EXP. These 2 new species represent the first records of the genus from Colombia and the second and third species known from the Caribbean. The number of species in the genus is now 45.

A new hyporheic Monchenkocyclops Karanovic, Yoo & Lee, 2012 (Crustacea: Copepoda) from Turkey with special emphasis on antennulary homology

Both sexes of Monchenkocyclops mehmetadami n. sp. were described from hyporheic freshwater habitat in Turkey. The new species can easily be distinguished from the other four species in the genus by having three setae on the inner margin of the second endopodal segment of the first and second swimming legs and four setae on the inner margin of second endopodal segment of the third and fourth swimming legs. The setation patterns of female and male antennules of the new species are analyzed with reference to the hypothetical 28- segmented antennule of ancestral copepod and the homology of the antennulary segments is determined in both sexes. Paraphyletic status of the genus is briefly discussed.

New Mesopsyllus species from the Bohai Sea, China, re-evaluation of the validity of Vibriopsyllus Kornev & Chertoprud, 2008 and proposal of Sympodella gen. n. (Copepoda, Harpacticoida, Canthocamptidae).

Two new species of the genus Mesopsyllus Por, 1960 (Canthocamptidae) are described from the Bohai Sea, eastern China. Mesopsyllus dimorphus sp. n. and M. spiniferus sp. n. differ from their congeners by the presence of two instead of three outer spines on P2–P3 exp-3. They can be differentiated from each other by (1) number of inner setae on P3–P4 enp-2; (2) anterior margin of antennulary segment 7 of male; (3) ornamentation of male abdomen; (4) sexual dimorphism on P2 endopod and P3–P4 exp-3; and (5) differences in length of setae on male P5. Some observations in the original description of M. atargatis Por, 1960 are reinterpreted and the type material of M. secundus (Wells, 1965) is re-examined. Comparison between the type species of Vibriopsyllus Kornev & Chertoprud, 2008 and the four known species of Mesopsyllus shows the former as a junior subjective synonym of the latter. Consequently, Vibriopsyllus curviseta Kornev & Chertoprud, 2008 is formally transferred to Mesopsyllus as M. curvisetus (Kornev & Chertoprud, 2008), comb. n. A key to species and an updated generic diagnosis of Mesopsyllus are presented.The taxonomic status of the genus Carolinicola Huys & Thistle, 1989 is re-evaluated. The characters of its type species, C. trisetosa (Coull, 1973), indicate that the latter (and – by inference – the genus Carolinicola) should remain in the Danielsseniinae. Carolinicola galapagoensis Mielke, 1997 is fixed as the type species of a new genus Sympodella gen. n. and placed in the Hemimesochrinae (Canthocamptidae) as the putative sistertaxon of Pusillargillus Huys & Thistle, 1989. The relationships and potential synonymy of the genera Pyrocletodes Coull, 1973, Perucamptus Huys & Thistle, 1989 and Isthmiocaris George & Schminke, 2003 are briefly discussed.

Caligus fajerae n. sp. (Copepoda: Caligidae) parasitic on the Pacific sierra Scomberomurus sierra Jordan & Starks (Actinopterygii: Scombridae) in the Pacific Ocean off Mexico.

A new species of parasitic copepod, Caligus fajerae n. sp. (Caligidae), is described from Scomberomorus sierra Jordan & Starks (Scombridae) caught off the northwestern coast of Mexico. The new species morphologically resembles Caligus cybii Bassett-Smith, 1898, Caligus kanagurta Pillai, 1961, Caligus pelamydis Krøyer, 1863 and Caligus robustus Bassett-Smith, 1898, all of which have been reported from scombrid hosts. Caligus fajerae n. sp. differs from these species by having spinules on the abdomen and caudal ramus, two processes on the proximal antennulary segment, fine striations on the claw of the antenna and maxilliped, a stouter and more recurved maxillulary dentiform process, shorter tines on the sternal furca, two additional patches of spinules on the distal endopodal segment of leg 2, a sclerotised lobe on the anteromedian surface of the leg 3 protopod and serrations on both margins of the first exopodal spine of leg 3. Analysis of the DNA sequences of the mitochondrial cytochrome c oxidase subunit 1 gene for Caligus fajerae n. sp. and 28 congeners, including C. pelamydis and C. robustus, showed that the new species grouped with Caligus belones Krøyer, 1863 (with 20% divergence), a species known to occur predominantly on needlefishes. Caligus fajerae n. sp. is the fifth species of Caligus reported from S. sierra. An updated host-parasite list for Caligus spp. on scombrids is provided.

A new Speleophria (Copepoda, Misophrioida) from an anchialine cave of the Yucatán Peninsula with comments on the biogeography of the genus

Misophrioid copepods are hyperbenthic or anchialine forms whose known distributional patterns appear to have a Tethyan origin and subsequent vicariant processes. A new misophrioid copepod, Speleophria germanyanezi n. sp., collected from an anchialine cave in Cozumel Island, Yucatan Peninsula (YP), is described based on male and female specimens. This is the second report describing a misophrioid copepod species from the Yucatan Peninsula, harboring a remarkably diverse anchialine crustacean fauna. The new species is the sixth of this anchialine genus. It differs from its congeners by a combination of characters including: the armature of leg 4 exopod, 21-segmented female antennule, 24-segmented male antennule, both with moderate proximal expansion, the male with the terminal antennulary segments distinctively elongate. The fifth leg distal segment is armed with 3 elements in the female, 4 in the male. The female genital double-somite is furnished with long, slender spinules. The other members of Speleophria are distributed in Europe (Croatia, Spain), Bermuda, and Australia. Relationships among species of Speleophria have revealed amphiatlantic pairs of sister taxa. The new species has little affinity with its regionally closest congener from Bermuda; it appears to be most closely related to the Croatian S. mestrovi and could be its western Atlantic counterpart. The different misophrioid fauna between the YP and Cozumel Island and the more recent emergence of Cozumel with respect to that of the YP plate suggests either an ancestral Tethyan-related independent colonization or a relatively recent local dispersal through deep-sea crevicular habitats before emergence of these land masses.