Mud Shrimp Research Articles

Diet composition and its relation to the characteristics of the digestive tract of the blue sea catfish, Ariopsis guatemalensis (Actinopterygii: Ariidae), in Barra de Navidad Lagoon, Jalisco, Mexico

Diet composition and the characteristics of the digestive tract of the blue sea catfish, Ariopsis guatemalensis, in a coastal lagoon in western Mexico were investigated. This species is consumed by locals and it has been used as a bioindicator of sewage pollution. This study aimed to determine if the feeding habits of this species were related to the macroscopic and microscopic morphological characteristics of the digestive tract. Specimens were captured in the Barra de Navidad Lagoon (Jalisco, Mexico) from 2011 to 2016. For every fish collected, total length (TL) was recorded and the esophagus, stomach, and intestine were extracted for histological analyses and identification of food items in their diet. The macroscopic and microscopic characteristics of the digestive tract and the stomach content analysis indicate A. guatemalensis is a carnivorous species with preference for goby fish. Crustaceans were the second most important food item and were dominated by portunid crabs and mud shrimps. The size and position of the mouth, the presence of dental plates on the vomer, palatines, premaxilla, and pharynx, and the presence of goblet cells in the digestive tract are characteristic of fishes that consume live hard-bodied prey and crush their food before it enters the esophagus. The relatively short intestine and the folds in the mucous membrane are characteristic of carnivorous fishes.

First detection of white spot syndrome virus (WSSV) in the mud shrimp Austinogebia edulis in Taiwan

The white spot syndrome virus (WSSV) causes mass mortalities in the aquaculture of shrimps worldwide. The mud shrimp Austinogebia edulis (Ngoc-Ho & Chan, 1992) is an economically important sea food item occurring along the west coast of Taiwan. While the population of A. edulis began to decrease with some fluctuations in the last decade, the current study aims to discover the causes for such sporadic population decline. This study explores the effects of microbial pathogens and innate immunity on the populations of A. edulis. Here, we report firstly about WSSV infection of A. edulis from the coastal zone of western Taiwan which is one of the possible causes of population decrease of A. edulis in Shengang. However, WSSV infection is not the only reason for its population decrease because a similar infection rate of WSSV was found in Wangong. Population changes may be related to both environmental pollution stress and WSSV. Both factors likely caused a massive reduction of hemocytes and an abnormal increase of phenoloxidase and superoxide dismutase activity, which were spectrophotometrically measured. Since there is no effective way to treat WSSV infection, improving the coastal environment appears the most effective way to increase the population size of feral shrimps.

The Prevalence of Macroparasite Infection in the Mud Shrimp Upogebia major (De Haan, 1841) (Decapoda: Gebiidea) from Peter the Great Bay, Sea of Japan

The peculiarities of infection with the parasitic bopyrid isopods Gyge ovalis and Progebiophilus sp. and the rhizocephalan Sacculina upogebiae among the mud shrimp Upogebia major population in Vostok Bay (Peter the Great Bay, Sea of Japan) were investigated in April–November 2017. Parasites were found from spring to late autumn. The prevalence of isopod infection in U. major was 5.42%, females and males were equally infected. The prevalence of Sacculina upogebiae was 1.26%; this parasite was more common on the female hosts. Isopods were found on mud shrimp larger than 42 mm; rhizocephalan externae occurred in individuals larger than 57 mm. The highest prevalence of parasites was observed in the summer (7.44%). No cases of simultaneous infection with different species of parasites were noted in U. major.

A new species of the mud shrimp genus Axianassa Schmitt, 1924 (Decapoda: Gebiidea: Laomediidae) from the Ryukyu Islands, southern Japan.

A new species of the laomediid mud shrimp genus Axianassa Schmitt, 1924, A. planioculus, is described and illustrated on the basis of a single male specimen from intertidal muddy sand flat of Kabira Bay, Ishigaki Island, southern Ryukyu Islands, Japan. Axianassa planioculus n. sp. is morphologically closest to A. mineri Boone, 1931, known from Pacific Panama, among the 11 known congeners, but is readily distinguished from the latter by the eyes being dorsally concealed by the rostrum, the subovate telson, the unarmed carpus of the maxilliped 3 and the unarmed uropodal endopod. The discovery of a new mud-shrimp species in an easily accessible habitat indicates that the shallow-water infaunal decapods are still relatively poorly known. A partial segment of the mitochondrial 16S rRNA gene was sequenced from the holotype for future genetic studies.

A slender symbiotic goby hiding in burrows of mud shrimp Austinogebia edulis in western Taiwan

The present study recorded the population of the goby fish (Perciformes: Gobiidae), Eutaeniichthys cf. gilli Jordan & Snyder, 1901, from the tunnel burrowed by the mud shrimp Austinogebia edulis Ngo-Ho and Chan, 1992 in a mudflat in Shengang and Wangong of Changhua County, western Taiwan. This finding is not only a new record of the genus in Taiwan, it is also the first record of this species in a mudflat near an industrial park. In total, 56 individuals of E. cf. gilli were collected from June 2016 to September 2018. Morphological traits of males and females were measured. The resin casting method trapped bodies of E. cf. gilli that were present in the tunnel burrow and proved that the fish inhabits burrows of the mud shrimp A. edulis. In addition, a species of snapping shrimp was also found in the same tunnel. Symbiotic interaction may occur between E. cf. gilli, A. eduli and the snapping shrimp. The China Coastal Current (CCC) runs along the coastlines of Japan, Korea, China, and reaches western Taiwan during the northeast monsoon period. The CCC, therefore, might play an important role in the biogeographic distribution of E. cf. gilli in the western Pacific Ocean. Since E. cf. gilli is listed in the Red List as an endangered species of Japan for many years, Taiwan waters may provide a refuge for this fish species warranting a broader investigation. Since Taiwan is some distance away from the previously recorded locations in Japan, Korea, the Yellow Sea, and the Bohai Sea, a phylogenic analysis is warranted for population and species differentiation in the future.

Seasonal influence of parasitism on contamination patterns of the mud shrimp Upogebia cf. pusilla in an area of low pollution.

Very few studies have characterized the concentrations of pollutants in bioturbating species. These species are considered as ecosystem engineers and characterizing stressors, such as contaminants, that impact them could lead to a better understanding of the functioning of ecosystems. In addition to contaminants, bioturbators are affected by a wide range of stressors, which can influence their physiological status and their ability to accumulate pollutants. Among these stressors, parasitism is of particular concern due to the ubiquity of parasites in natural environments and their influence on the fitness of their host. This study aims to assess the relationship between parasitism and metal accumulation in the bioturbating mud shrimp Upogebia cf. pusilla. A one-year seasonal survey was conducted in Arcachon Bay, France, with the aims of (1) characterizing the levels of metals in the mud shrimp and (2) evaluating the influence of two macroparasites (a bopyrid isopod and a trematode) on the variation of the metal content in mud shrimp. The bopyrid parasite castrates its female host and a particular attention has therefore been paid to the reproductive cycle of female mud shrimp by quantifying the expression of the vitellogenin gene that encodes the major yolk protein in female crustaceans. The levels of contaminants in mud shrimp appeared low compared to those reported in other crustaceans in areas of higher pollution. Even at these low contamination levels, we observed a significant impact by the bopyrid parasite that depends on season: bopyrid-infested organisms are generally more contaminated than their uninfested conspecifics except in summer when the opposite trend was observed. We suggest that the bopyrid indirectly interferes with the metal accumulation process by altering the reproductive capabilities of the mud shrimp. On the opposite, very low influence of the trematode parasite on the metal content of the host was found.

Further records of burrow-associated palaemonid shrimps (Decapoda: Palaemonidae).

Despite the ubiquitous nature of symbiosis in palaemonid shrimps (Caridea: Palaemonidae) which live in or on varied invertebrate hosts, such as echinoderms, sponges, ascidians, hard and soft corals, etc., very few taxa have been recorded living in burrows constructed by other animals. This is in sharp contrast to the rich burrow-dwelling diversity in the Alpheidae, in which numerous genera associate with a great variety of burrowing animals, including stomatopods (Hayashi 2002; Ďuriš Anker 2014), echiurans (Anker et al. 2005, 2015), other alpheid shrimps (e.g. De Grave 2004; Anker Marin 2006), and especially numerous ghost and mud shrimps (e.g. Anker, 2011; Anker Lazarus 2015).

Linking behaviours, sediment reworking, bioirrigation and oxygen dynamics in a soft-bottom ecosystem engineer: The mud shrimp Upogebia pusilla (Petagna 1792)

Despite the role of bioturbation in controlling biogeochemical processes taking place at the sediment-water interface, little is still known about how animal behaviours influence sedimentary biogeochemical processes. In the present work, we used the mud shrimp Upogebia pusilla as model organism to assess the effect of behaviour types/intensities on sediment reworking, bioirrigation and sediment oxygen dynamics based on three sets of seasonal experiments. We identified four main behaviours: “Resting”, “Walking”, “Ventilating” and “Burrowing”. Mud shrimp were much more active (i.e., not “Resting”) during summer than during winter and to a lesser extent spring due to elevated temperature. There were three distinct components of sediment reworking. The first one consisted in the expulsion of sediment particles from the burrow to the sediment-water interface, the second one to the transfer of sediment downward within the burrow and the third one to the transport and compaction of sediment across burrow walls. Temporal changes in the intensities of all components correlated tightly since they all resulted from “Burrowing”. The temporal dynamics of porewater exchange and oxygen dynamics were clearly discontinuous and in direct relation with “Ventilating”. However, other behaviours, and especially “Burrowing” were also involved in the control of this dynamics through the modulation of oxygen availability within the burrow, which is cuing the onset of ventilation at a 12–25% saturation threshold. These results underline the importance of taking into account changes in animal behaviour types/intensities at the appropriate temporal scales when assessing the impact of bioturbation on biogeochemical processes taking place at the sediment-water interface.

Assessment of CH4 oxidation in macroinvertebrate burrows of tidal flats

In tidal flats that lack plants, methane (CH4) fluxes are both positive (gas emission) and negative (gas “sinking”) in nature. The levels of methanotroph populations significantly affect the extent of CH4 sinking. This preliminary study examined CH4 flux in tidal flats using a circular closed-chamber method to understand the effects of macroinvertebrate burrowing activity. The chamber was deployed over decapods (mud shrimp, Laomedia astacina and crab, Macrophthalmus japonicus) burrows for ~ 2 h, and the CH4 and CO2 concentrations were continuously monitored using a closed, diffuse CH4/CO2 flux meter. We found that Laomedia astacina burrow (which is relatively long) site afforded higher-level CH4 production, likely due to diffusive emission of CH4 in deep-layer sediments. In addition, the large methanotrophic bacteria population found in the burrow wall sediments has CH4 oxidation (consumption) potential. Especially, nitrite-driven anaerobic oxidation of methane (AOM) may occur within burrows. The proposed CH4-oxidation process was supported by the decrease in the δ13C of headspace CO2 during the chamber experiment. Therefore, macroinvertebrate burrows appear to be an important ecosystem environment for controlling atmospheric CH4 over tidal flats.

Effects of cadmium exposure on antioxidant enzymes and histological changes in the mud shrimp Austinogebia edulis (Crustacea: Decapoda).

The trace metal cadmium (Cd) is a toxic pollutant known to induce oxidative stress and other sublethal to lethal effects on aquatic organisms. We exposed the marine mud shrimp Austinogebia edulis to Cd concentrations of 0, 0.5, and 5mg/kg for up to 4days (24, 48, 72, 96h). We studied the activity of antioxidant enzymes in the hepatopancreas, gill, and muscle of A. edulis. Antioxidant enzymes (SOD, CAT, and GPx) decreased with increasing Cd concentration and extended exposure time in these three organs of the mud shrimp A. edulis. Increasing Cd concentration led to an increase in ROS and resulted ultimately in membrane lipid peroxidation at higher Cd concentrations. Significant damage of the hepatopancreas of A. edulis was noticed at higher concentrations of Cd, showing damages like the disappearance of epithelial cell boundaries, detachment of cells from the basal lamina, cellular swelling, necrosis, and reduction of glycogen. In conclusion, Cd caused oxidative damage by reducing the activities of antioxidant enzymes and by damaging the tissue structure in major organs of the mud shrimp A. edulis.

Comparison of Sedimentary Environmental Characteristic of Tidal Flats on the West Coast of Korea Depending on the Habitation of Mud Shrimp Upogebia major

Comparison of Sedimentary Environmental Characteristic of Tidal Flats on the West Coast of Korea Depending on the Habitation of Mud Shrimp Upogebia major

가재붙이(갑각강, 가재붙이과) 서식굴 내 영양염의 일간 변화

본 연구의 목적은 큰 규모의 서식굴(가재붙이) 내부에서의 조석에 따른 산소 및 영양염 변동을 파악하고, 갯벌 퇴적물의 영양염 순환에 있어 큰 서식굴이 미치는 영향 정도를 파악하는 것이다. 이를 위해 서식굴을 파괴하지 않으면서 굴 내부의 환경을 측정할 수 있는 관찰구를 근소만 갯벌 현장퇴적물 속에 설치하고, 서식굴 내부의 산소 및 영양염의 일간 변동을 조사하였다. 가재붙이(L. astacina) 서식굴 내부의 영양염 농도는 노출시와 침수시 그리고 낮과 밤 동안에 뚜렷한 차이를 나타내며 일변화를 보였다. 특히 용존성무기질소의 경우에 그러한 경향이 뚜렷하였으며, 이는 굴 내부의 온도와 산소농도 조건에 따라 암모늄화, 질산화, 탈질산화 작용이 선택적으로 일어나고 있음을 지시하였다. 가재붙이 서식굴을 통한 영양염의 플럭스도 하루 중 밀물과 썰물 그리고 낮과 밤 간에 뚜렷한 일변화를 보였으며, 그 양은 갯벌 표층(자연상태의 대형저서동물 개체수 유지)을 통한 플럭스의 23∼224% 범위에 있었다. 가재붙이와 같이 큰 굴을 가지며 활발하게 관개활동을 하는 생물의 서식굴이 갯벌 퇴적물과 해수 간의 영양염 순환에 보다 중요한 의미를 가질 수 있음을 시사하였다. 동일 조사지역에서 각기 다른 방법으로 측정된 영양염 플럭스 결과 비교에서 현장에서 직접 측정한 본 조사의 경우에 기존에 일반적으로 사용되고 있던 챔버를 이용한 퇴적물 배양법이나 미세전극을 이용한 플럭스 계산법에 비해 훨씬 높은 플럭스가 계산되었다. 기존의 방법을 통한 플럭스 계산에는 일정 이상의 규모를 가진 생물에 의한 플럭스 영향을 충분히 고려하지 못했기 때문인 것으로 판단되었다. 이로부터 가재붙이와 같이 큰 규모의 서식굴을 가지는 종이 갯벌 퇴적물의 영양염 순환에 미치는 영향이 지대함을 알 수 있었다. 따라서 조석 변동과 큰 규모의 서식굴을 반영하지 않은 갯벌의 영양염 플럭스 산출은 과소평가 될 수 있었다.

How does the bopyrid isopod Gyge branchialis interfere with trace metal bioaccumulation in the mud shrimp Upogebia cf. pusilla?

Parasites are widespread in natural environments, and their impacts on the fitness of their host and, at a broader scale, on ecosystem functioning are well recognized. Over the last two decades, there has been an increasing interest in the effects of parasites in conjunction with other stressors, especially pollutants, on the health of organisms. For instance, parasites can interfere with the bioaccumulation process of contaminants in their host leading to parasitized organisms exhibiting lower pollutants burdens than unparasitized individuals for example. However, the mechanisms underlying these patterns are not well understood. This study examined how the bopyrid parasite Gyge branchialis could lower the cadmium (Cd) uptake of its mud shrimp host Upogebia cf. pusilla. When exposed to water-borne Cd, parasites were able to bioaccumulate this trace metal. However, the uptake of Cd by the parasite was low and cannot entirely explain the deficit of Cd contamination of the host. The weight of gills of parasitized organisms was significantly reduced compared with unparasitized organisms. We suggest that by reducing the surface for metal uptake, parasites could lower the contaminant burden of their host.

Do trace metal contamination and parasitism influence the activities of the bioturbating mud shrimp Upogebia cf. pusilla?

Mud shrimp are considered as among the most influential ecosystem engineers in marine soft bottom environments because of their significant bioturbation activity and their high density. These organisms play a key role on the physical structure of sediments through intense sediment reworking activity and also deeply influence geochemical properties of sediments via frequent bioirrigation events. The influence that mud shrimp have on the environment is related to the magnitude of bioturbation processes and subsequently depends on their physiological condition. In natural environments, several factors act together and influence the well-being of organisms. Among them, the deleterious role of parasites on the physiology and the behavior of their host is well established. Aquatic organisms are also subject to pollutants released by anthropogenic activities. However, the effect of both stressors on the fitness and bioturbation activity of mud shrimp has never been investigated yet.We conducted a 14-day ex-situ experiment to evaluate the influence of trace metal contamination (cadmium Cd) and parasitism infestation on the gene expression (molecular endpoint) and sediment reworking activity (behavioral endpoint) of the mud shrimp Upogebia cf. pusilla. At completion, mud shrimp exhibited substantial Cd bioaccumulation, with parasitized organisms showing a significantly lower contaminant burden than unparasitized specimens. Cadmium contamination induces modifications of gene expression in both unparasitized and parasitized organisms. We report an antagonistic effect of both stressors on gene expression, which cannot be fully explained by a lower Cd bioaccumulation. At the behaviour level, parasitism seems to reduce the sediment reworking activity of mud shrimp, while Cd contamination appears to stimulate this activity. This study highlights that the effects of multiple stressors may be quite different from the effects of each stressor considered individually. It should also motivate for more studies evaluating the influence of multiple stressors on different endpoints encompassing various levels of organization.

Effect of glazing and rosemary (Rosmarinus officinalis) extract on preservation of mud shrimp (Solenocera melantho) during frozen storage

In this study, glazing with water and rosemary (Rosmarinus officinalis) extract were applied on frozen mud shrimp (Solenocera melantho) and stored at −20 °C for 24 weeks. Quality loss and protein and lipid changes of shrimp were evaluated by total volatile basis nitrogen (TVB-N), drip loss, moisture distribution, sulfhydryl content (SH), disulfide bond, intrinsic fluorescence intensity, lipid content, free fatty acids (FFA), peroxide value (PV), fluorescent compounds and sensory characteristics. Results showed that unglazed mud shrimp exhibited significant quality decline after 16 weeks of frozen storage. Glazing treatment significantly reduced quality loss, protein degradation, and lipid oxidative damage of shrimp during the 24 weeks of frozen storage, compared to the unglazed control sample. Glazing with rosemary extract was more effective in controlling quality changes in frozen mud shrimp with lower TVB-N, drip loss, PV, FFA and higher lipid content and sensory scores.

Influence of the bioturbator Upogebia cf. pusilla on trace metal remobilization: Does parasitism matter?

Marine sediments are an important source of contaminants since they are susceptible to be remobilized to the water column. By modifying the physical and biogeochemical characteristics of sediments, bioturbation can influence contaminants remobilization. Within bioturbators, mud shrimp are considered as among the most influential organisms in marine soft-bottom environments. The physiological state of mud shrimp can be impaired by bopyrid parasites. The present study aims to evaluate the influence of bopyrid-uninfested and bopyrid-infested mud shrimp on sediment contaminants resuspension. Through a 14-days ex-situ experiment we showed a moderate effect of mud shrimp on contaminant remobilization compared to molecular diffusion without the bioturbator. Conversely, parasite presence significantly impaired contaminant bioaccumulation in mud shrimp and interfered with genetic expression. The weak effect of mud shrimp on contaminant remobilization may be due to trace metal accumulation and thus we suggested to evaluate the influence of contaminants on activities of bioturbating species.

Insights into Macroinvertebrate burrowing Activity and Methane Flux in Tidal Flats

Kang, J.; Koo, B.J.; Jeong, K.-S.; Woo, H.J.; Seo, J.; Seo, H.-S.; Kim, M.-S., and Kwon, K., 2018. Insights into macroinvertebrate burrowing activity and methane flux in tidal flats. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 681–685. Coconut Creek (Florida), ISSN 0749-0208.The CH4 flux was examined preliminarily in tidal flats using a circular closed-chamber method to understand the effects of macroinvertebrate burrowing activity. The chamber was deployed over decapods (mud shrimp, Laomedia astacina and crab, Macrophthalmus japonicus) burrows for ~ 2 h, and the CH4 and CO2 concentrations were continuously monitored using a closed, diffuse CH4/CO2 flux meter. It founds that Laomedia astacina burrow (which is relatively long) site afforded higher-level CH4 production, likely due to diffusive emission of CH4 in deep-layer sediments. In addition, the proposed CH4-oxidation process (i.e., reverse methanogenesis) was supported by the decrease in the δ13C of headspace CO2 during the chamber experiment. Therefore, macroinvertebrate burrows appear to be an important ecosystem environment for controlling atmospheric CH4 over tidal flats.

Seasonal and habitat structures of crustacean decapod assemblages associated withZostera marinabeds in northern Jinhae Bay, Korea

Crustacean decapod assemblages were surveyed inZostera marinabeds adjacent to tidal flats (ET) and rocky shore (ER), and in unvegetated habitats (UV). Decapod samples were collected monthly throughout 2002 using a small beam trawl from northern Jinhae Bay, Korea. Water temperature, salinity, eelgrass biomass, sediment composition and organic matter were also monitored to assess any correlation between environmental variables and decapod fauna. A total of 31 decapod species belonging to five taxa (three prawns, 13 caridean shrimps, one hermit crab, one mud shrimp and 13 crabs) were collected at three different habitats. To assess variations in decapod assemblages in relation to habitat type and season, various multivariate analyses were used. The dominant caridean shrimps werePalaemon macrodactylus, Alpheus digitalisandCrangon uritai,and the dominant crabs wereCharybdis japonica, Hemigrapsus penicillatusandCharybdis bimaculata. The number, abundance and diversity of decapod species varied greatly with habitat type and season, peaking in eelgrass beds and during spring, and showing the lowest catch rate in unvegetated habitat and during winter months. The nMDS ordination and multivariate analyses revealed that habitat type and season were determinant factors affecting the structure of decapod assemblages. Seasonal shifts in the abundance of decapods corresponded with changes in eelgrass biomass and loss on ignition (LOI), but not with water temperature or salinity.

More cautionary tales: family, generic and species synonymies of recentlypublished taxa of ghost and mud shrimps (Decapoda: Axiidea and Gebiidea).

Re-examination of the holotype of Neoaxius nicoyaensis Sakai, 2017 showed that it is conspecific with the axiid Guyanacaris caespitosa Squires, 1979 and thus Neoaxius Sakai, 2017 and Neoaxiidae Sakai, 2017 are respectively subjective junior synonyms of Guyanacaris Sakai, 2011 and Axiidae Huxley, 1879. The types and numerous specimens of the callianassid Trypaea vilavelebita Sakai Türkay, 2012 are juveniles of the common northeastern Atlantic-Mediterranean species, Callianassa subterranea (Montagu, 1808); the name is therefore a subjective junior synonym. The monotypic callianopsid genera Pleurocalliax Sakai, 2011, Neocallianopsis Sakai, 2011 and Phaetoncalliax Sakai, Türkay, Beuck Freiwald, 2015 are found not to differ from Callianopsis de Saint Laurent, 1973, the only alleged differences found to be untrue or trivial. Phaetoncalliax mauritana Sakai, Türkay, Beuck Freiwald, 2015 and Neocallianopsis africana Sakai, Türkay, Beuck Freiwald, 2015 are thereby transferred to Callianopsis, the latter a subjective junior synonym of the former. Contrary to the assertion of its author, the gourretiid Pseudogourretia portsudanensis Sakai, 2005, the only species in its genus, has no pleurobranchs. The genus Pseudogourretia Sakai, 2005 is therefore synonymised with Gourretia de Saint Laurent, 1973. The respective holotypes of Paracalliax stenophthalmus Sakai, Türkay, Beuck Freiwald, 2015 and Paracalliax bollorei de Saint Laurent, 1979 were re-examined. Both are from the Banc d'Arguin, off Mauritania, and are identical at the species level. The upogebiid Kuwaitupogebia nithyanandan Sakai, Türkay Al Aidaroos, 2015 from Kuwait is identical to Upogebia balmaorum Ngoc-Ho, 1990 from the Seychelles, Madagascar and tropical Western Australia. Kuwaitupogebia Sakai, Türkay Al Aidaroos, 2015 is therefore synonymised with Upogebia Leach, 1814 and Kuwaitupogebiidae Sakai, Türkay Al Aidaroos, 2015 with Upogebiidae Borradaile, 1903.

First record of Naushonia sp. (Decapoda: Laomediidae) larva from the Equatorial Atlantic.

The first zoeal-stage larva of a possibly new species of mud shrimp Naushonia (Decapoda: Gebiidea: Laomediidae) was described from plankton samples taken off the Fernando de Noronha Archipelago, being the first occurrence at the oceanic islands of the Equatorial Atlantic. Five zoea I larvae were obtained and dissected for observation of mouthparts. This zoea I of Naushonia sp. is well distinguished from the first larvae of N. portoricensis (Rathbun 1901) from the Caribbean and N. cangronoides (Kingsley 1897) from the Northwest Atlantic in terms of development and setation of appendages, and possibly belongs to a new, undescribed species. The present study widens the knowledge on tropical oceanic decapod larvae and provides detailed drawings and new photographic illustrations with extended depth of field of these organisms.