Species Of Caprellid Amphipods Research Articles

Habitat selection of intertidal caprellid amphipods in a changing scenario

Habitat selection is a complex process, dependent on numerous fluctuating conditions and key to species coexistence. In a changing global scenario, it will greatly determine the fate of marine organisms and hence is an important subject to be explored. The present study evaluates host specificity of two caprellid amphipod species, Caprella grandimana and Caprella takeuchii, dwelling on a rocky intertidal where the calcifying macroalgae Jania rubens and Ellisolandia elongata show opposite seasonal fluctuation patterns throughout the year. To avoid confounding preference with other factors, the substrate selection experimental design included both multiple choice and non-choice treatments. Macroalgal structure analyses using fractals and interstitial space index were included in the study, as substrate complexity is a main factor driving preference for epifauna. Caprella grandimana actively selected J. rubens, whereas C. takeuchii did not show any preference; both behaviours remaining consistent regardless of the original substrate. Preference for J. rubens is probably owed to its interstitial space and thalli characteristics, as the complexity analysis suggested, since these allow for better refuge against predators and a more suitable surface for grasping. Meanwhile, the plasticity of C. takeuchii seems to favor an ongoing taking over of its congener at the time of the year when J. rubens drops. We highlight the need for rigor when performing substrate selection experiments; the importance of including habitat selection lessons in conservation strategies and modelling studies dealing with global change; and the risk in generalizing results within the family or genus level, which is occasionally inadequate for understanding the functioning of the ecosystem as a whole.

Indirect effects of predators control herbivore richness and abundance in a benthic eelgrass (Zostera marina) mesograzer community.

Herbivore communities can be sensitive to changes in predator pressure (top-down effects) and resource availability (bottom-up effects) in a wide range of systems. However, it remains unclear whether such top-down and bottom-up effects reflect direct impacts of predators and/or resources on herbivores, or are indirect, reflecting altered interactions among herbivore species. We quantified direct and indirect effects of bottom-up and top-down processes on an eelgrass (Zostera marina) herbivore assemblage. In a field experiment, we factorially manipulated water column nutrients (with Osmocote(™) slow-release fertilizer) and predation pressure (with predator exclusion cages) and measured the effects on herbivore abundance, richness and beta diversity. We examined likely mechanisms of community responses by statistically exploring the response of individual herbivore species to trophic manipulations. Predators increased herbivore richness and total abundance, in both cases through indirect shifts in community composition. Increases in richness occurred through predator suppression of common gammarid amphipod species (Monocorophium acherusicum and Photis brevipes), permitting the inclusion of rarer gammarid species (Aoroides columbiae and Pontogeneia rostrata). Increased total herbivore abundance reflected increased abundance of a caprellid amphipod species (Caprella sp.), concurrent with declines in the abundance of other common species. Furthermore, predators decreased beta diversity by decreasing variability in Caprella sp. abundance among habitat patches. Osmocote(™) fertilization increased nutrient concentrations locally, but nutrients dissipated to background levels within 3m of the fertilizer. Nutrient addition weakly affected the herbivore assemblage, not affecting richness and increasing total abundance by increasing one herbivore species (Caprella sp.). Nutrient addition did not affect beta diversity. We demonstrated that assemblage-level effects of trophic manipulations on community structure are the result of distinct and often indirect responses of herbivore species. These results underscore the importance of understanding herbivore-herbivore interactions in a system commonly subjected to both eutrophication and overfishing.

Nutritional analysis of freshwater and marine amphipods from the Strait of Gibraltar and potential aquaculture applications

Four gammarid and four caprellid amphipod species from the Strait of Gibraltar were analyzed to study their nutritional contents: Caprella dilatata, Caprella equilibra, Caprella grandimana, Caprella penantis, Elasmopus rapax, Hyale perieri and Jassa sp. from marine water habitats and Echinogammarus sp. from freshwater habitats. Lipids, proteins, carbohydrates, ash and water contents were measured. Proteins and ash were the most abundant components in all the species, ranging between 37.9 and 44.6% and 29.3 and 39.7% dry weight, respectively. The lipid and carbohydrate contents showed lower levels (5.1–9.6% and 3.1–9.1% dry weight, respectively). No significant differences in general biochemical composition were found between gammarid and caprellid species. The most abundant fatty acids were the polyunsaturated ones (38.3%) with high levels of EPA (20:5(n-3)) with 8.5 to 17.7%, DHA (22:6(n-3)) with 0.9 to 13.6% and ARA (20:4(n-6)) with 1.7 to 5.8%. Caprellid species were characterized by a higher percentage of polyunsaturated fatty acids, while the freshwater gammarid species showed the lowest levels. According to lipid classes, caprellids had higher phospholipids levels and lower triacylglycerol levels, as well as a higher content of polar lipids than the gammarids, being more suitable for their use in aquaculture. Differences in the general biochemical composition between species can be related to habitat characteristics, diets and environmental conditions. Advantages and disadvantages of the use of these organisms in aquaculture are discussed.

The tropical caprellid amphipod Paracaprella pusilla: a new alien crustacean in the Mediterranean Sea

Paracaprella pusilla Mayer (Fauna und Flora des Golfes von Neapel 17:1–55, 1890), originally described from Brazil, is one of the most abundant caprellid amphipod species in tropical and subtropical seas around the world. During a survey of caprellid amphipods from marinas along the Balearic Island (Western Mediterranean Sea) carried out between November 2011 and August 2012, we found two established populations of P. pusilla in Mallorca and Ibiza, respectively. So far, its occurrence in European waters was reported only from southwestern Spain in 2010. This record represents a northward range expansion of the species’ distribution, which is found for the first time in the Mediterranean. This is also the first record of the genus Paracaprella in the Mediterranean Sea. The most probable introduction vector was ship fouling. We also found the invasive caprellid Caprella scaura Templeton (Trans Entomol Soc Lond 1:185–198, 1836) in Mallorca and Menorca, which is recorded for the first time in the Balearic Islands, confirming its rapid expansion along the Mediterranean. When comparing reproductive traits between both alien species, we found that P. pusilla has a higher fecundity than C. scaura for the same female size. Taking into account this evidence, the species may be expected to appear in other Mediterranean and adjacent areas.

The Caprellidea (Crustacea: Peracarida: Amphipoda) from the Gulf of Mexico with a description of a new species of <i>Paracaprella</i>

A new species of caprellid amphipod of the genus Paracaprella is described and illustrated in detail. All the material reported was collected from coral rubble samples from the Arrecife Tuxpan/Lobos Protected Natural Area, off Veracruz State, Mexico, WSW Gulf of Mexico. The new species is characterized by large eyes; article 2 of peduncle of antenna 2 with a distoventral process; body dorsally setose; large subrectangular projection on the anteroventral margin of pereonite 2; basis of gnathopod 2 elongate and thin with a proximal knob on posterior margin, propodus longer than broad, with a robust grasping spine, and a large and robust tooth distally; and pereopods 5, 6 and 7 with several long plumose setae. The new species increases the numbers of Paracaprella species recorded around the world to 8, and the caprellid species from the Gulf of Mexico to 16. All caprellid amphipod species documented from this gulf inhabit the coastal zone and six in the deep sea. In addition, the number of caprellid species decreases along the bathymetric gradient: 15 species on the littoral zone, 6 on the continental shelf, 5 on the continental slope, and 3 on the abyssal plain.

The re-description and distribution of two new records (Amphipoda: Caprellidae) from the Egyptian Red Sea coast

Two caprellid amphipod species namely; Pseudocaprellina pambanensis Sundara Raj, 1927 and Hemiaegina minuta Mayer, 1890, were recorded as a part of the amphipod fauna associated with macroalgae in the coast of Hurghada Red Sea. The re-description and illustrations of the two species are based on the examination of 4627 individuals, 88% of them were P. pambanensis and the rest were H. minuta. The two caprellid species were collected from six sites scattered over Hurghada coast and their distribution and abundance were investigated.

On the occurrence of the tropical caprellid Paracaprella pusilla Mayer, 1890 (Crustacea: Amphipoda) in Europe

Paracaprella pusilla MAYER, 1980 is a tropical caprellid amphipod species first described from Brasil and very common along the Atlantic coast of Central America. Since its original description, P. pusilla has been found at numerous widespread locations in tropical and subtropical seas around the world, primarily associated with fouling communities in harbours. An established population of P. pusilla was recently found in Cádiz, southern Spain, which is both the northernmost collection and first record of this species in European coastal waters. Ship fouling is the most probable vector for its introduction. The species was always found associated with the native hydroid Eudendrium racemosum (CAVOLINI, 1785) and appeared to display a mutualistic relationship with this host.

Geometric morphometric analysis discriminates native and non-native species of Caprellidae in western North America

Characteristics of the second gnathopod are traditionally used to distinguish between species of caprellid amphipods. However, these distinctions are often subjective and can be variable within a species. Geometric morphometrics were used to quantitatively assess shape variation of the second gnathopod propodus of three species of caprellids in North America, including the non-nativeCaprella mutica. Gnathopod shapes ofC. muticaspecimens from different latitudes revealed distinct morphologies; the factors responsible for the shape variations are unknown. Allometric change of propodus shape was observed inC. mutica. Larger individuals showed a wide array of possible propodus morphologies. Despite this variability, there were clear differences between large specimens ofC. muticaand two species native to North America:C. alaskanaandC. kennerlyi. The use of geometric morphometrics and the thin-plate spline method can serve to both complement descriptions using traditional keys and aid in identification of non-native species in novel geographical regions.

Acute toxicity of tributyltin to the Caprellidea (Crustacea: Amphipoda).

In order to compare the acute toxicity of tributyltin (TBT) between sexes, five species of caprellid amphipods were exposed to seven levels (0, 0.001, 0.01, 0.1, 1, 10 and 100 microg l(-1)) of TBT for 48 h at 20 degrees C. The 48-h LC50 values in male and female were 1.3-6.4 microg TBTCl l(-1) and 1.2-8.6 microg TBTCl l(-1), respectively. No sex-specific differences of the acute toxicity of TBT were observed in the caprellids. These findings suggest that the risk of survival in response to exposure to TBT between sexes is similar in the caprellids.

Morphological characteristics of young, maternal care behaviour and microhabitat use by caprellid amphipods

Microhabitat use by nine species of caprellid amphipods in the genus Caprella inhabiting a Japanese Sargassum bed could be divided into three major categories. Differences in the patterns of use were closely related to the nature of the mother–young association and morphological characteristics of young. Pattern A was shown by three species Caprella danilevskii, C. okadai and C. subinermis that produced large first instar young (>1.6 mm in body length, BL) with no maternal care, and directly use Sargassum thalli as habitat substrata throughout their lives. Two different patterns of microhabitat use occur in the six other species, which produce small first instar young (<1.3 mm BL) and have trouble using Sargassum thalli as their primary habitat. Pattern B comprised of C. decipiens, C. monoceros and C. scaura in which females care for their young until they become large enough to disperse onto the seaweed thalli. The first instar young of these three maternal care species have specialized pereopods. In Caprella monoceros and C. scaura, which show a ‘cling-to-mother’ type of maternal care, each pereopod has a concaved margin on the propodus and a long dactylus, well adapted for clinging to the mother, and C. decipiens, which show a ‘stay-around-mother’ type of maternal care, have comparatively slender and longer pereopods to hold onto seaweed branches near their mother. Pattern C included C. arimotoi, C. glabra and C. penantis which showed no maternal care and use thin branches of epizoites such as epiphytic hydroids as their primary substrata. It is concluded that caprellids that live on seaweed with thick thalli and branches such as Sargassum patens have different solutions to the problem of where the small first instar young can live: species with larger young emerge directly onto seaweed thalli, but species with smaller young use an epiphytic secondary habitat or depend on maternal care.

Fatty Acid Compositions in Four of Caprellid Amphipod Species (Crustacea) from Otsuchi and Mutsu Bays in Northern Japan

Analysis was made of lipid classes and fatty acid compositions in four species of caprellid amphipods (Crustacea) from Otsuchi and Mutsu Bays in northern Japan. Total lipid content ranged from 1.42.3% wet weight with triacylglycerol (TG) and phosphatidylcholine (PC) as the lipids most abundantly present. Major fatty acid compositions of total lipids (TL) were in most cases 16 : 0, 18 : 1 (n-9), 20 : 5 (n-3), and 22 : 6 (n-3), constituting 4763% the whole. The amount of 20 : 5 (n-3), the most predominant polyunsaturated fatty acid, in TL was remarkably higher in the cool than warm temperature species (2932% in the former and 2122% in the latter). Differences in TL fatty acid compositions for the two groups were shown to arise from PC in the principal membranes, whereas fatty acid compositions of TG from either group were essentially the same.

Comparative Study of Mother-Young Association in Caprellid Amphipods: Is Maternal Care Effective?

ABSTRACT Mother-young association was examined in 9 species of caprellid amphipods in the genus Caprella. Five species: Caprella arimotoi, C. danilevskii, C. glabra, C. okadai, and C. penantis showed no interaction between mother and young after emergence from her brood pouch, but various degrees of prolonged cohabitation of young with their mother were observed in the other four species. In Caprella subinermis, though no maternal care was observed, the first instars remained on the body of the mother for up to 4 days, and then dispersed before the first molt. Aggregations of young protected by the mother were observed in the other 3 species. Aggregations of a mother with multiple cohorts of young were found in Caprella decipiens, while C. monoceros and C. scaura had single cohorts of young on or around the body of the mother. Based on field data and results of field-rearing experiments, the cohabiting period is up to 30 days in C. decipiens and up to 20 days in C. monoceros. For 5 species having different degrees of mother-young association, one-month field-rearing experiments under predator-free conditions were conducted. The results showed that the presence of the mother increased both the survival and growth rate of the young in C. monoceros,but the presence of the mother increased only the growth rate in C. scaura. In the other 3 species, C. danilevskii, C. decipiens, and C. subinermis, the presence of the mother did not positively affect either survival or growth of the young.

Caprellid amphipod behavior and predatory strikes by fish

Fish predation upon two species of caprellid amphipods was measured in the laboratory with the aid of microcomputer analysis of video-images. This technique allowed determination of prey preferences when the predator was exposed to multiple prey specimens exhibiting multiple prey behaviors. Shiner perch Cymatogaster aggregata (Gibbons) were used as visual predators, Caprella laeviuscula Mayer represented caprellid prey which frequently move, and Deutella californica Mayer represented caprellid prey which seldom move. Time intervals between the release of fish into the test aquarium and predatory strikes were measured during four caprellid behaviors: free in the water column, crawling on hydroids, filter-feeding by pulling the antennae through the water, and remaining stationary. There are three levels of fish selectivity in decreasing importance: 1. (1)fish selected active species over the sedentary species, 2. (2) fish selected caprellids that were overtly moving: swimming > crawling or filtering > stationary, and 3. (3) fish preferentially selected caprellids by size (larger body length).

Three Species of Caprellid Amphipods from Ogasawara Islands, with a Description of a New Species

Three Species of Caprellid Amphipods from Ogasawara Islands, with a Description of a New Species

Ecology of two littoral species of caprellid amphipods (Crustacea) from Washington, USA

Ecology of 2 littoral species of caprellid amphipods is compared. Populations of Caprella laeviuscula, a periphyton scraper/filter-feeder, are most dense on eelgrass Zostera marina L. In the absence of C. laeviuscula, periphyton biomass increases 411% in protected Z. marina beds. The light absorption spectra of periphyton and Z. marina are similar, and C. laeviuscula, by its periphyton removal, may allow Z. marina to grow in areas where it would otherwise be excluded. C. laeviuscula is aggressively dominant over sympatric caprellids, and seasonal predators of C. laeviuscula are absent during winter, the period when periphyton would be most limiting to Z. marina. Populations of Deutella californica, a predator, are most dense on the hydroid Obelia dichotoma (L.). In the O. dichotoma epibiotic community, D. californica is the primary predator, but removal did not change the composition of the community structure. In the absence of other macropredators, the structure of the O. dichotoma epibiotic community depends more on the seasonality of O. dichotoma occurrence than on organismal interactions.

Population structures of two species of Caprellid amphipods (Crustacea)

Population structures of Caprella laeviuscula Mayer and Deutella californica Mayer are compared and factors structuring the populations are discussed. Instars were determined by the number of articles in the antennules. The number of D. californica per instar continuously decreased after emergence from the brood pouch. Populations of Caprella laeviuscula had 1. 1) an initial decrease in numbers, 2. 2) an increase in cohort size at middle instars, and 3. 3) decreasing population size. For both species population declines were caused by molting-related deaths. Population structures of C. laeviuscula were also caused by selective predation, intraspecific conflict during amplexus, and by rapidly molting juveniles becoming slow molting as adults. Deviations from a 1 : 1 sex ratio in C. laeviuscula were attributed to selective predation on females. Differences in the age of becoming sexually mature reduce the probability that a chance predator would remove all mature females.

Comparative functional morphology of feeding in three species of caprellids (Crustacea, Amphipoda) from the northwestern Florida Gulf Coast

The functional morphology of feeding has been investigated in three species of caprellid amphipods. Feeding preferences are correlated with the increased setation and stoutness of the head appendages, the denser the setae the greater the trend toward filter-feeding. It was found that Caprella penantis Leach fed primarily by filter-feeding and scraping; Paracaprella tenuis Mayer relied on filter-feeding, scraping, scavenging, and predation; and Luconacia incerta Mayer depended almost entirely on predatory habits. The observed feeding patterns were verified by stomach content analysis.

The Caprellidae (Crustacea: Amphipoda) of Virginia

Five species of caprellid amphipods occur in Virginia waters:Aeginina longicornis, Hemiaegina minuta, Paracaprella tenuis, Caprella equilibria, andCaprella geometrica. Though all are offshore species, the latter three commonly occur within Chesapeake Bay.Deutella abracadabra is placed as a juniro synonym ofParacaprella tenuis and the nameCaprella geometrica is assigned to the “acutifrons” form found along the Atlantic and Gulf of Mexico coasts of the United States.