The life cycle of the Tantulocarida (Crustacea)

1987 ◽  
Vol 315 (1173) ◽  
pp. 267-303 ◽  
Keyword(s):  
Life Cycle ◽  
Adult Female ◽  
Adult Male ◽  
Deep Sea ◽  
The Body ◽  
Dispersal Ability ◽  
Free Living ◽  
Unique Type ◽  
High Dispersal ◽  
Living Adult

Four new species of parasitic crustaceans belonging to the class Tantulocarida are described, two of which are placed in a new genus, Onceroxenus . Three of them parasitize deep-sea tanaids, the other, a deep sea asellote. Microdajus langi , originally classified as an epicaridean isopod, is recognized as a tantulocaridan. It is reported from Scottish waters for the first time and from new host species. These records include the shallowest depth, 22 m, known for a tantulocaridan. Cumoniscus kruppi a parasite of cumaceans, is also recognized as a tantulocaridan. The Tantulocarida now comprises eleven species and five genera, here assigned to the Basipodellidae and two new families, the Deoterthridae and Microdajidae. Several life cycle stages are described and arranged in two developmental sequences. Evidence for a possible third sequence was found. Male development involves a unique type of metamorphosis in which the free-living adult differentiates from a dedifferentiated mass of tissue contained within the expanded trunk of the tantulus larva. Throughout this metamorphosis the male is supplied with nutrients from the host via a tissue connection, the umbilical cord, and the permanently attached larval head. The non-feeding adult male lacks cephalic appendages but possesses two clusters of aesthetascs on its anterior margin. It is free swimming and has six pairs of large thoracopods without endites. The first two thoracic somites are incorporated into the cephalothorax. The abdomen bears a posteriorly directed, median stylet, interpreted as the intromittent organ. It originates on the first abdominal somite. The adult female has a large sac-like trunk attached by the larval head. The larval trunk is sloughed leaving a scar but no complete moult occurs. Eggs develop within the trunk sac and hatch directly at the infective tantulus larval stage. This extreme condensation of early ontogeny is compared with that of other crustaceans and is interpreted as an adaptation to parasitism in situations where a high dispersal ability is not advantageous. In some females the trunk sac forms behind the head but the larval trunk is retained. Small and large females of this type are described, the largest being 737 µm in length. These probably represent females in which sloughing of the larval trunk has failed but it is possible that each may have contained a free-living adult female of comparable size to the adult male. The tantulus larva is described in detail. Scanning electron microscopy reveals that the thoracopodal endites have a complex apical armature, including coupling spines which serve to link the members of a leg pair. Tantulocaridans are permanently attached to their host by the oral disc, presumably by means of an adhesive. In the centre of the disc they make a minute puncture (between 0.5 and 2.0 µm in diameter) through the host integument, probably with the aid of their cephalic stylet. This constitutes their only access to the body fluids of the host. The phylogenetic relationships of the Tantulocarida are discussed. They appear to be related to the barnacles (Thecostraca), both groups possessing a median penis derived from the seventh trunk limb. Their possession of a thorax of six somites and the location of the male gonopores on trunk somite seven suggests an affinity with a larger group containing the Thecostraca and the Copepoda.

On the histological anatomy of Benthimermis megala Petter, 1987, a giant nematode from the Norwegian deep-sea (Nematoda: Benthimermithidae)

Nematology ◽  
2001 ◽  
Vol 3 (6) ◽  
pp. 491-502 ◽  
Author(s):  
Alexei Tchesunov ◽  
Dmitry Miljutin
Keyword(s):  
Deep Sea ◽  
Mouth Opening ◽  
The Body ◽  
Head Region ◽  
Free Living ◽  
Larval Stages ◽  
Germinal Zone ◽  
Female Genital System ◽  
Living Adult ◽  
Female Genital

AbstractFree-living adult stages of Benthimermis megala Petter, 1987, the biggest species (body length 78 - 148 mm) of the genus, have been found in bottom sediments of the deep-sea off the Norway coast and studied histologically. The head region includes six subcuticular sensilla, four minute cephalic setae and pore-like amphids. Numerous tiny sensilla are distributed throughout the lateral sides of the body. An axial spine is present on the posterior body terminus. Hypodermal glands are associated with the somatic sensilla. There are eight chords in the hypodermis. Mouth opening is absent. Vestigial pharynx is glandular and devoid of an internal lumen. Midgut is a trophosome made up of large radial cells and a very thin axial internal lumen. The trophosome cells are filled with various inclusions, which are reduced in size and number with age. A few cuticular grains are present in a vestigial rectum. The nerve ring is embedded in the anterior trophosome. The female genital system is amphidelphic. The germinal zone of the ovaries extends the length of the gonad (hologonic ovary), whereas the ovaries of smaller Benthimermis species are telogonic. Neither spermatozoa nor spermatheca in female ducts were identified. No males of B. megala were found. Obviously, larval stages parasitise benthic invertebrates, while non-feeding adult stages dwell freely in sediment and reproduce.

scholarly journals Dispersal and Differentiation of Deep-Sea Mussels of the GenusBathymodiolus(Mytilidae, Bathymodiolinae)

2009 ◽  
Vol 2009 ◽  
pp. 1-15 ◽  
Author(s):  
Akiko Kyuno ◽  
Mifue Shintaku ◽  
Yuko Fujita ◽  
Hiroto Matsumoto ◽  
Motoo Utsumi ◽  
...  
Keyword(s):  
Gene Flow ◽  
Genetic Differentiation ◽  
Shallow Water ◽  
Deep Sea ◽  
Dispersal Ability ◽  
Evolutionary Transition ◽  
Significant Genetic Differentiation ◽  
Evolutionary Processes ◽  
High Dispersal ◽  
High Gene

We sequenced the mitochondrial ND4 gene to elucidate the evolutionary processes ofBathymodiolusmussels and mytilid relatives. Mussels of the subfamily Bathymodiolinae from vents and seeps belonged to 3 groups and mytilid relatives from sunken wood and whale carcasses assumed the outgroup positions to bathymodioline mussels. Shallow water mytilid mussels were positioned more distantly relative to the vent/seep mussels, indicating an evolutionary transition from shallow to deep sea via sunken wood and whale carcasses.Bathymodiolus platifronsis distributed in the seeps and vents, which are approximately 1500 km away. There was no significant genetic differentiation between the populations. There existed high gene flow betweenB. septemdierumandB. breviorand low but not negligible gene flow betweenB. marisindicusandB. septemdierumorB. brevior, although their habitats are 5000–10 000 km away. These indicate a high adaptability to the abyssal environments and a high dispersal ability ofBathymodiolusmussels.

scholarly journals Studies on the Life Cycle of Some New Zealand Anisakidae (Nematoda)

2021 ◽  
Author(s):  
◽  
Rosemary Jennifer Hurst
Keyword(s):  
Life Cycle ◽  
New Zealand ◽  
Body Cavity ◽  
The Body ◽  
In Vitro Cultivation ◽  
Free Living ◽  
Larval Stages ◽  
Factors Influencing ◽  
Phocarctos Hookeri

<p>The life cycle of Anisakis simplex in New Zealand waters is described from observations on the morphology, distribution and behaviour of free-living and parasitic stages. Comparison with the life cyles of two other anisakids, Phocanema decipiens Myers 1959 and Thynnascaris adunca Rudolphi 1802 shows differences in distribution, degrees of host specificity, the status of invertebrate hosts, the factors influencing infestation levels of teleost hosts, and the location and pathological effects of infestation. Larval stages occurring in intermediate and paratenic hosts were identified by comparison of larval and adult morphometrics. A. simplex larvae were also positively identified by in vitro cultivation through to adults. Some morphometric variations compared to overseas descriptions are apparent. The ventriculus of A. simplex larvae is shorter relative to body length and the intestinal caecum of P. decipiens is longer relative to ventriculus length. Egg and free-living larval stages were obtained from in vitro cultivation of (A. simplex) and collection of eggs from mature adults from definitive hosts (T. adunca). Eggs of P. decipiens were not obtained. Eggs of A. simplex and T. adunca hatch in 8-11 days at 15 [degrees] C. A. simplex eggs hatch in 6 days at a temperature of 22 [degrees] C and did not hatch in 16 days at 10 [degrees] C. Eggs and free-living stage III larvae of A. simplex and T. adunca are similar in morphology with little differentiation of internal structures. Examination of the stomach contents of pelagic fish infested with anisakids indicated that possible intermediate hosts of A. simplex are the euphausiid Nyctiphanes australis and the decapod Munida gregaria. Possible hosts of T. adunca and M. gregaria are a wide variety of smaller zooplanktonic groups, e.g. decapod larvae and copepods. Larvae of A. simplex were found in one of 8850 N. australis; larvae of T. adunca were found in 69 of 3999 chaetognaths (Sagitta spp.) a medusa and a decapod larva. These larvae are morphologically similar to Stage III larvae from teleosts. No anisakids were found in 3956 Euphausia spp., 1147 M. gregaria and 740 prawns. Twenty five T. adunca larvae and adults were found in 818 freshly eaten M. gregaria in teleost stomachs, indicating that this invertebrate may act as a paratenic and a definitive host. Experimental infection of N. australis and M. gregaria with stage II larvae of A. simplex and T. adunca was unsuccessful. The location of anisakid infestation in three pelagic teleost species, Thyrsites atun, Trachurus novaezelandiae and Trachurus declivis is described. A. simplex larvae are found mainly in the body cavity of all species, at the posterior end of the stomach, with less than one percent occurring in the musculature. Distribution of A. simplex larvae does not change with increasing size of the host or increasing total worm burden. Thyrsites atun have a higher proportion of larvae in the stomach wall (8-13%) compared to Trachurus spp. (< 4%). T. adunca larvae are found infrequently in the body cavity of all three species, on the pyloric caeca and in the stomach wall. Adults and larvae of T. adunca are found more commonly in the alimentary canal, indicating that these teleosts are more important as definitive hosts in the life cycle of this anisakid. P. decipiens larvae are found only in Thyrsites atun and occur mainly in the muscles (98.5%). No quantitative pathogenic effects of anisakid infestation on these teleosts hosts were detected. The main factors influencing the infestation of the three teleost species are age of the host, locality and season. Sex of the host and depth (over the continental shelf, 0-250 m) are not important. A. simplex infestation increased with age in all host species examined, and was higher in Trachurus declivis from the southern-most locality, suggesting the existence of at least two distinct populations of this species. Significant differences in infestation of Thyrsites atun with P. decipiens suggests that this anisakid may be more common in southern localities also. The infestation of Thyrsites atun by larval and adult T. adunca in the alimentary canal is most influenced by season and closely related to diet. Nematode samples were obtained from the marine mammals Arctocephalus forsteri, Kogia breviceps and Phocarctos hookeri. Adult A. simplex were recorded from A. forsteri (a new host record) and Kogia breviceps; preadults from Phocarctos hookeri. Adult P. decipiens were recorded from Phocarctos hookeri; preadults from Arctocephalus forsteri and K. breviceps. Other anisakids found were Anisakis physeteris (Baylis 1923), Contracaecum osculatum Rudolphi 1802 and Pseudoterranova kogiae (Johnston and Mawson 1939) Mosgovoi 1951. These records are all new for the New Zealand region except P. decipiens from P. hookeri and C. osculatum from Arctocephalus forsteri. A. simplex and C. osculatum were found associated with gastric ulcers in Arctocephalus forsteri.</p>

scholarly journals Studies on the Life Cycle of Some New Zealand Anisakidae (Nematoda)

2021 ◽  
Author(s):  
◽  
Rosemary Jennifer Hurst
Keyword(s):  
Life Cycle ◽  
New Zealand ◽  
Body Cavity ◽  
The Body ◽  
In Vitro Cultivation ◽  
Free Living ◽  
Larval Stages ◽  
Factors Influencing ◽  
Phocarctos Hookeri

<p>The life cycle of Anisakis simplex in New Zealand waters is described from observations on the morphology, distribution and behaviour of free-living and parasitic stages. Comparison with the life cyles of two other anisakids, Phocanema decipiens Myers 1959 and Thynnascaris adunca Rudolphi 1802 shows differences in distribution, degrees of host specificity, the status of invertebrate hosts, the factors influencing infestation levels of teleost hosts, and the location and pathological effects of infestation. Larval stages occurring in intermediate and paratenic hosts were identified by comparison of larval and adult morphometrics. A. simplex larvae were also positively identified by in vitro cultivation through to adults. Some morphometric variations compared to overseas descriptions are apparent. The ventriculus of A. simplex larvae is shorter relative to body length and the intestinal caecum of P. decipiens is longer relative to ventriculus length. Egg and free-living larval stages were obtained from in vitro cultivation of (A. simplex) and collection of eggs from mature adults from definitive hosts (T. adunca). Eggs of P. decipiens were not obtained. Eggs of A. simplex and T. adunca hatch in 8-11 days at 15 [degrees] C. A. simplex eggs hatch in 6 days at a temperature of 22 [degrees] C and did not hatch in 16 days at 10 [degrees] C. Eggs and free-living stage III larvae of A. simplex and T. adunca are similar in morphology with little differentiation of internal structures. Examination of the stomach contents of pelagic fish infested with anisakids indicated that possible intermediate hosts of A. simplex are the euphausiid Nyctiphanes australis and the decapod Munida gregaria. Possible hosts of T. adunca and M. gregaria are a wide variety of smaller zooplanktonic groups, e.g. decapod larvae and copepods. Larvae of A. simplex were found in one of 8850 N. australis; larvae of T. adunca were found in 69 of 3999 chaetognaths (Sagitta spp.) a medusa and a decapod larva. These larvae are morphologically similar to Stage III larvae from teleosts. No anisakids were found in 3956 Euphausia spp., 1147 M. gregaria and 740 prawns. Twenty five T. adunca larvae and adults were found in 818 freshly eaten M. gregaria in teleost stomachs, indicating that this invertebrate may act as a paratenic and a definitive host. Experimental infection of N. australis and M. gregaria with stage II larvae of A. simplex and T. adunca was unsuccessful. The location of anisakid infestation in three pelagic teleost species, Thyrsites atun, Trachurus novaezelandiae and Trachurus declivis is described. A. simplex larvae are found mainly in the body cavity of all species, at the posterior end of the stomach, with less than one percent occurring in the musculature. Distribution of A. simplex larvae does not change with increasing size of the host or increasing total worm burden. Thyrsites atun have a higher proportion of larvae in the stomach wall (8-13%) compared to Trachurus spp. (< 4%). T. adunca larvae are found infrequently in the body cavity of all three species, on the pyloric caeca and in the stomach wall. Adults and larvae of T. adunca are found more commonly in the alimentary canal, indicating that these teleosts are more important as definitive hosts in the life cycle of this anisakid. P. decipiens larvae are found only in Thyrsites atun and occur mainly in the muscles (98.5%). No quantitative pathogenic effects of anisakid infestation on these teleosts hosts were detected. The main factors influencing the infestation of the three teleost species are age of the host, locality and season. Sex of the host and depth (over the continental shelf, 0-250 m) are not important. A. simplex infestation increased with age in all host species examined, and was higher in Trachurus declivis from the southern-most locality, suggesting the existence of at least two distinct populations of this species. Significant differences in infestation of Thyrsites atun with P. decipiens suggests that this anisakid may be more common in southern localities also. The infestation of Thyrsites atun by larval and adult T. adunca in the alimentary canal is most influenced by season and closely related to diet. Nematode samples were obtained from the marine mammals Arctocephalus forsteri, Kogia breviceps and Phocarctos hookeri. Adult A. simplex were recorded from A. forsteri (a new host record) and Kogia breviceps; preadults from Phocarctos hookeri. Adult P. decipiens were recorded from Phocarctos hookeri; preadults from Arctocephalus forsteri and K. breviceps. Other anisakids found were Anisakis physeteris (Baylis 1923), Contracaecum osculatum Rudolphi 1802 and Pseudoterranova kogiae (Johnston and Mawson 1939) Mosgovoi 1951. These records are all new for the New Zealand region except P. decipiens from P. hookeri and C. osculatum from Arctocephalus forsteri. A. simplex and C. osculatum were found associated with gastric ulcers in Arctocephalus forsteri.</p>

Nematode morphogenesis: fine structure of the molting cycles in Panagrellus silusiae (de Man 1913) Goodey 1945

1969 ◽  
Vol 47 (4) ◽  
pp. 639-643 ◽  
Author(s):  
M. R. Samoiloff ◽  
J. Pasternak
Keyword(s):  
Protein Synthesis ◽  
Fine Structure ◽  
Adult Female ◽  
Adult Male ◽  
Early Stage ◽  
Free Living ◽  
Microscopic Evidence ◽  
Molting Process ◽  
Free Living Nematode ◽  
De Man

The mode of formation of a new cuticle in the free-living nematode Panagrellus silusiae is similar at each of the three postpartum molts. Molting begins with the appearance of filaments adjacent to the hypodermis. The new cuticle accumulates material and lacks organization during the early stage of the molt. The edge of the new cuticle adjacent to the old cuticle is composed of an amorphous row of particles and a filamentous region abuts the hypodermis. Eventually, a complete cuticle is produced beneath the preexisting one.The shedding of the old cuticle varies in different molts. In the larval molts (L2 to L3 and L3 to L4) and the molt to the adult female the cuticle is discarded piecemeal. During the molt to the adult male the old cuticle splits and is shed as a single piece.Before completion of ecdysis in the final female molt, the new cuticle folds extensively. This folding does not occur during any other molt.Resorption of the old cuticle is never observed. There is no microscopic evidence of protein synthesis in the interchordal hypodermis during the molting process.

scholarly journals A new ortheziid (Hemiptera: Coccoidea) from Australia associated with Acropyga myops Forel (Hymenoptera: Formicidae) and a key to Australian Ortheziidae

Zootaxa ◽  
2008 ◽  
Vol 1946 (1) ◽  
pp. 55-68 ◽  
Author(s):  
JOHN S. LAPOLLA ◽  
CHRIS BURWELL ◽  
SEÁN G. BRADY ◽  
DOUGLASS R. MILLER
Keyword(s):  
Adult Female ◽  
Adult Male ◽  
New Genus ◽  
Scale Insect ◽  
Instar Nymph ◽  
The Body ◽  
Female Adult ◽  
Morphological Attributes ◽  
First Instar ◽  
Anal Ring

A peculiar new genus of Ortheziidae is described from Queensland, Australia. Acropygorthezia williamsi LaPolla & Miller, n. gen. & sp. was discovered in two localities in the nests of Acropyga myops. Descriptions and illustrations are provided for the adult female, adult male, first-instar nymph, prepupa, and pupa; descriptions only are provided for the secondand third-instar nymphs. Prior to this study, Acropyga ants were known to enter into trophobiotic relationships only with mealybugs (Hemiptera: Pseudococcidae). Therefore, this study represents the first non-mealybug association between a scale insect and Acropyga. The new ortheziid genus has a number of unusual morphological attributes: no definite wax plates; no ovisac; an anal ring lacking setae and pores, located dorsally in the middle of the abdomen; simple, large metasternal and mesosternal apophyses; numerous spines over the body, and various instars that are so similar that they are difficult to separate. These characteristics may represent adaptations to its relationship with ants. A key is provided to the Australian Ortheziidae.

Some observations on Pseudomenopon pilosum (Amblycera: Menoponidae), the louse vector of Pelecitus fulicaeatrae (Nematoda: Filarioidea) of coots, Fulica americana (Aves: Gruiformes)

1989 ◽  
Vol 67 (5) ◽  
pp. 1328-1331 ◽  
Author(s):  
Cheryl M. Bartlett ◽  
R. C. Anderson
Keyword(s):  
Adult Female ◽  
Adult Male ◽  
Gallus Gallus ◽  
The Body ◽  
Stage Larva ◽  
Western Canada ◽  
Fulica Americana ◽  
Breeding Populations ◽  
Third Stage ◽  
Podiceps Grisegena

Breeding populations of Pseudomenopon pilosum (Scopoli, 1763) became established on 10 laboratory-reared juvenile American Coots (Fulica americana Gmelin) initially infested with 5 adult male and 5 adult female lice. Eggs of P. pilosum hatched less than 10 days after deposition and the combined duration of the three nymphal instars was 10–20 days. Nymphs and adults occupied all regions of the body. Pseudomenopon pilosum might thus acquire microfilariae of Pelecitus fulicaeatrae (Diesing, 1861) by simply randomly moving to and feeding on the legs where, in infected coots, the skin-inhabiting microfilariae of P. fulicaeatrae are known mainly to occur. Pseudomenopon pilosum occurred on all of 13 adult coots and three 1-week-old coot chicks collected in June in western Canada where P. fulicaeatrae is enzootic. Third-stage larvae of P. fulicaeatrae were found in adult P. pilosum on two of four adult coots harbouring microfilariae, but prevalence in lice was low (5.5% of 18 lice on one coot and 1.1% of 90 on the second) and only one third-stage larva was present in each infected louse. Four other species of lice were present on adult coots but only one other on 1-week-old chicks. Experiments showed that P. pilosum could occur as a straggler on chickens (Gallus gallus (L.)) and Red-necked Grebes (Podiceps grisegena (Boddaert)) although it did not establish on either species.

The Life Cycle of Symbiotic Crustaceans

2018 ◽  
pp. 375-402
Author(s):  
J. Antonio Baeza ◽  
Emiliano H. Ocampo ◽  
Tomás A. Luppi
Keyword(s):  
Life Cycle ◽  
Life Cycles ◽  
The Body ◽  
Free Living ◽  
Major Life ◽  
Ground Pattern ◽  
Symbiotic Relationships ◽  
Larval Stages ◽  
Phylogenetic Inertia ◽  
Vertebrate Hosts

In the subphylum Crustacea, species from most major clades have independently evolved symbiotic relationships with a wide variety of invertebrate and vertebrate hosts. Herein, we review the life cycle disparity in symbiotic crustaceans. Relatively simple life cycles with direct or abbreviated development can be found among symbiotic decapods, mysids, and amphipods. Compared to their closest free-living relatives, no major life cycle modifications were detected in these clades as well as in most symbiotic cirripeds. In contrast, symbiotic isopods, copepods, and tantulocarids exhibit complex life cycles with major differences compared to their closest free-living relatives. Key modifications in these clades include the presence of larval stages well endowed for dispersal and host infestation, and the use of up to 2 different host species with dissimilar ecologies throughout their ontogeny. Phylogenetic inertia and restrictions imposed by the body plan of some clades appear to be most relevant in determining life cycle modifications (or the lack thereof) from the “typical” ground pattern. Furthermore, the life cycle ground pattern is likely either constraining or favoring the adoption of a symbiotic lifestyle in some crustacean clades (e.g., in the Thecostraca).

Moulting and mating in Lepeophtheirus pectoralis (Copepoda: Caligidae)

1990 ◽  
Vol 70 (2) ◽  
pp. 269-281 ◽  
Author(s):  
Morten Anstensrud
Keyword(s):  
Adult Female ◽  
Anterior Margin ◽  
Ventral Side ◽  
Dorsal Side ◽  
The Body ◽  
Agonistic Behaviour ◽  
Free Living ◽  
Genital Complex ◽  
Frontal Filament ◽  
Receptaculum Seminis

Prior to moulting, the preadult Lepeophtheirus pectoralis produces a temporary frontal filament which attaches the animal to the surface of the host during ecdysis. This filament is extruded from a frontal organ previously thought to have a chemoreceptory function. During ecdysis the exuvium splits at the anterior margin and is shed posteriorly by contractions of the body. After hardening of the exoskeleton the copepod detaches itself from the frontal filament and is free-living on the host during intermoult. Males in precopula position hold on to the dorsal side of the female, with the second antennae grasping the anterior end of the female's genital complex. During the ecdysis of the female, most males release their hold on the female, and are usually found close to her on the host. Copulation occurs between an adult male and an adult female with a hardened exoskeleton. In the copula position the male holds on to the female's genital complex with the second antennae, but now on the ventral side of the female. Two spermatophores are extruded and then transferred simultaneously to the female with the aid of the second pair of swimming legs. Tubes originating from the spermatophores connect them to the orifices of the receptaculum seminis. These tubes seem to grow out of the spermatophores after expulsion. After copulation, the male retains a precopula position before releasing the female. No agonistic behaviour has been observed between a precopulating/copulating male and additional males. However, during the ecdysis of the female, a new male may take over the female, but mating does not seem to be assortative for size in Lepeophtheirus pectoralis.

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