Select the search type
  • Site
  • Web

Student Project

Palaemon serrifer (Stimpson, 1860)

Craig Regan 2015


General summary

Palaemon serrifer (Stimpson, 1860), known by its common name as the Barred Estuarine Shrimp, is a decapod crustacean of the infraorder Caridea. Approximately three-quarters of the roughly 2800 species of carideans live in marine environments, spanning all regions of the world except Antarctica (DeGrave et al., 2008; Schram et al., 2010). P. serrifer occupies estuarine areas in parts of Australia and the indo-west-pacific, particularly associated with seagrass and rocky areas (Davie et al., 2010).

Observation reveals immediately their long antennae and their conspicuous eyes. In adult females, some indivduals bear a conspicuous egg mass that is held amongst their pleopods (refer to “Anatomy” section for more detailed description). They have a diverse range of neural, osmoregulatory and chemosensory apparatus and functions.

Whilst it hasn’t yet been assessed for the IUCN red list, the conservation of P. serrifer is nonetheless intertwined with that of the seagrass beds which they occupy, and rely on. 


Palaemon serrifer (Stimpson, 1860)

Common name: Barred Estuarine Shrimp

                Phylum                Arthropoda
                Subphylum          Crustacea
                Superclass          Multicrustacea
                Class                    Malocostraca
                Subclass               Eumalocostraca
                Superorder         Eucarida
                Order                    Decapoda
                Suborder             Pleocyemata
                Infraorder           Caridea
                Superfamily       Palaemonoidea
                Family                  Palaemonidae
                Subfamily           Palaemoninae
                Genus                   Palaemon
                Species               Palaemon serrifer

(Retrieved [May, 19 , 2015], from the Integrated Taxonomic Information System on-line database,

Physical Description

General Description

figure image
Image 1 – Bird’s eye view of individual P. serrifer. (Image: Craig Regan, 2015)

The individual shown in Image 1 measures 72mm from the tip of the antennae to the tip of the telson,and 45mm from the tip of the rostrum to the tip of the telson (For more detail refer to the “Anatomy” section). Indivduals typically maintain a hunched position, with their abdomen  curving ventrally. 

Being this size, they can often be quite difficult to see in the water, particularly in considering that they have a translucent-white colouration. This translucence, however,makes it quite easy to view some of their internal anatomy particularly in the head region.

Note the conspicuous compound eyes, situated on their ocular peduncles that jut out laterally from the head region. Just anterior to these are the antennae, extending approximately 35mm.

Whilst not clearly shown in Image 1, the 1st perepod is well developed into a claw-like chelae, typical of the family Palaemonidae. Its uses include the mechanical manipulation of items such as food. Refer to Video 3, in the “Anatomy”section, of an individual using its chelae to pick off a portion of a dead crab, then consume it. 

They move quite slowly, unless threatened, when they will escape backwards from the threat by way of a quick tail-flick. (Refer to Video 4 in "Anatomy" section to see this escaping beahvaiour). 

Figure 1


Below is a dichotomous key for the identification of P.serrifer, from the level of the superfamily Palaemonoidea to species level. Sourced from Bruce (1993).                                                                                                                                            

1. Well developed chelae of first pereopod. Mandible with incisor process prominent, deeply separated from molar process. First maxiliped with caridean lobe acutely produced distally.

Family Palaemonidae 2                       

2. Telson usually with 2 pairs of posterior marginal spines.

Subfamily Palaemoninae    3                          

3. Carapace with branchiostegal spine, and branchiostegal suture extending posteriorly from anterior margin. Elevated dentate crest at base of rostrum. Mandible normally with palp.

Genus Palaemon 4
  1. 4. 2 or 3 teeth of dorsal rostrum situated on carapace, posterior to level of orbital margin. Rostrum usually nearly horizontal, basal antennular segment with spine barely overreaching adjacent distal margin of segment.

Species Palaemon serrifer


As the name suggests, the Barred Estuarine Shrimp lives in estuarine areas, particularly amongst rocks and seagrass (Davie et al., 2002).Whilst there doesn’t exist a great deal of information specific to P. serrifer in regard to their ecology and their interactions with the environment, there are comparisons that can be made between it and other crustaceans.

In general, extrinsic factors such as temperature, salinity, light availability and oxygen concentration are important for the biology of crustaceans (Emmerson, 1985). Temperaure has obvious effects as one would expect from an ectotherm, with respiration rate rising with increases in temperature (Allan et al., 2006).  

With changes in salinity, however, the effects aren’t so clear-cut. A range of factors contribute to salinity tolerance, though responses vary amongst different species (Huni & Aravindan, 1984). Kirkpatrick & Jones, (1985) showed that larger individuals of the species Palaemon affinis had higher survival rates when exposed to adverse salinity. Other studies, however, show that tolerance may decrease with increasing size (Jones, 1981). This highlights that there is a complex interplay of factors that determine what environmental conditions the organism can handle, and the ecological niche in which they can occupy.  

In general, however, findings indicate that species of Palaemon that inhabit brackish or marine environments are capable of both hypo and hyper-osmotic regulation, enabling them to tolerate fluctuating salinities (Kirkpatrick& Jones, 1985). This allows for them to inhabit a wider ecological niche.

Within this ecological niche, the shrimp play an important role. There is evidence that shrimp predation plays a crucial part in regulating meiofaunal communities, by way of reducing their abundance, whilst not effecting the diversity of major species (Bell & Coull, 1978). Convsersely, with shrimp being prey for various other species, fluctuations in the abundance of the shrimp can have knock-on effects for the abundance of their predators, and vice-versa (Frank et al., 2005).  

Life History and Behaviour

Life History

Although little is available in the literature regarding breeding of the Australian populations of P. serrifer, populations in the Yellow Sea tend to breed in the summer and spring, (Kim, 2008). Embryo size is a determinate factor in various life history traits, and is highly positively correlated with growth rate and fecundity (Kim, 2008).   

P. serrifer is iteroparous, reaching sexual maturity quickly through investing a large amount of initial energy to growth and most of the remainder  to reproduction (Kim, 2008). The life span of P. serrifer is estimated to be around 13 – 16 months (Ito, 1991).

Eggs are attached on the posterior side of the abdomen, carried amongst the pleopods, a trait common to shrimp of the suborder Pleocyemata (Burkenroad, 1963). The eggs have an incubation period of between 11 and 19 days (Ito, 1991).

When eggs are undergoing hatching, they trigger the larval release behaviour of the parent, involving pumping of the abdomen and beating of the pleopods to mechanically assist in the release of eggs (Forward et al., 1987; Ziegler & Forward, 2007a). Studies on decapods have shown that pheromone release by the hatching eggs is a key component in triggering this behaviour (De Vries et al., 1991; Ziegler & Forward, 2007b).

Research Project


Cleaning behaviour, involving the removal of ectoparasites from other organisms is a mutualistic, symbiotic process, described by Feder (1966). It has been observed across a wide range of organisms, such as birds, fish, ants, lizards and crustaceans (Nicolette, 1990). As of a study by Becker & Grutter (2004), there were a confirmed 43 species of cleaner shrimp amongst this range of cleaning organisms. 

Whilst no research has been conducted on the cleaning habits of P. serrifer there exist various studies on other shrimp within the family Palaemonidae that highlight the importance of this trait. The shrimp Periclimenes holthuisi has been found to remove 75% of monogenea (Benedenia sp.) from its host (Becker & Grutter, 2004). The Pederson Cleaning Shrimp (Periclimenes pedersoni) was also shown to play a significant role in biological regulation of ectoparasites (McCammon et al., 2010).

Despite this relative shortage of scientific evidence, there does exist anecdotal evidence of interactions with divers and wild shrimp, where the shrimp will clean parts of the diver’s mouth as though they were a fish. Similar stories exist regarding shrimp in captivity. I aim to investigate the cleaning activity of P. serrifer.

For this, I will place various items in the tank, and determine which items the shrimp have a preference for cleaning. The items to be placed in the tank are:

- My hand
- An empty shell
- A scourer rubbed in algae
- A dead crab

I chose these particular items because I expect that they will yield very different responses, but I hypothesise that the algae covered scourer will be the most preferred. This hypothesis is based on previous observations I have made of the shrimp feeding on algae that had accumulated on the sides of the tank, as can be seen in Video 1. 

Video 1 - Individual P. serrifer feeding on algae at the bottom of the tank.


The items were placed in the same position in the tank, one after the other, each for a period of 10 minutes. During this time, observations were taken as to how long it took for cleaning to begin, how long individuals remained on the item, and how many individuals were involved. Items were kept still for the duration.


The shrimp showed no interest in my hand, and indeed were deterred by it. I had placed my hand in the tank many times previously, and each time they fled away from it (using their characteristic powerful tail flick to quickly escape the unfamiliar intruder). I was interested to see whether keeping it still for 10 minutes might acclimatise them to it to some extent. It seemed they became at least accustomed to it, in that after some time they were happy to swim closer to it, but at no point did they touch my hand.

As for the gastropod shell, I expected this would be more popular than it was. Over the course of the 10 minutes, only 5 individuals in total approached it, but not one of them stayed longer than 4 seconds, only stopping to inspect it and move on. They weren´t interested in it.

The scourer was slightly more successful, though still didn´t attract a great deal of attention. Only 3 individuals approached it. However, unlike with the shell, one individual remained for 13 seconds to feed on the algae that was on its surface, before moving on.

By far the most preferred of the items was the dead crab. At 1min 16sec after its placement, there were 5 individuals feeding on different parts of it. Following this, individuals came and went frequently. I noticed a very interesting behaviour, in that there was clearly physical competition for the crab. At 4min 25sec, one individual became defensive, and warded off other shrimp that attempted to share in the food.This continued until the end of the 10 minute period, with the dominant shrimp changing throughout this time, as newcomers would either be warded off, or succeed in overthrowing the occupying shrimp. This behaviour is captured in Video 2. 

Video 2 - Competition over food source between indivduals.


In regard to the experimental design itself, there are 2 key points to note. The first is that there exists nothing in the literature to confirm that P. serrifer are truly cleaners by way of engaging in mutualistic symbiotic relationships with various other organisms through removal of parasites.

The second point relates to a drawback in the experimental design in that it doesn’t accurately replicate the natural setting of the cleaning relationship. I selected objects arbitrarily, choosing them for their being highly varied. They were designed to test the range of possible preferential targets for the shrimps attention.

With this in mind, this experiment allowed some insight into what is better described as simple feeding behaviour as opposed to true cleaning. The shrimp showed a marked preference towards the dead crab, suggesting that they may be detritivorous, as well as feeding on algae. 

Anatomy and Physiology


figure image
Image 2P. serrifer, with anatomical labelling. Labelling based after Mclaughlin, (1980). (Image: Craig Regan, 2015)

The body of the shrimp is divided into two main sections – the cephalothorax (itself, as the name indicates, a fusion of the head and thorax) and the abdomen (also called the pleon).

Encasing the cephalothorax, is the shield-like carapace, which extends down laterally to cover the gills, and the bases of the pereopods (thoracic limbs). There are 5 pairs of pereopods and, whilst not clearly visible in the image above, the terminal end of the 1st pereopod is modified to form a distinct claw-like structure known as the chelae. This is characteristic of the family Palaemonidae (Bruce, 1993).

In general, chelae serve a variety of functions including prey capture and manipulation, reproduction, defense and competition (Buric et al., 2009). I observed individuals using their chelae in feeding, to grasp and remove parts of food and bring it to their mouthparts for consumption. Refer to Video 3, of a shrimp using the chelae to tear of and eat a portion of dead crab. As a result of the translucency of the individual you can clearly see the food portion being swallowed down.

Video 3 - Individual P. serrifer using chelae to remove, and eat portion of dead crab. Can also
see food being swallowed down by the individual. (Video: Craig Regan, 2015)

Directly observing the shrimp revealed that the remaining peropods (2-5) serve a function of locomotion, allowing the shrimp to walk along the bottom of their tank.

Forming part of the complex mouth structure are the maxillipeds. These, along with mandibles, are modified appendages sitting anteriorly to the pereopods that serve in feeding (Garm & Hoeg, 2001). The detailed mouthparts are not clearly visible in Image 2.

Located dorsally, at the anterior end of the carapace is the rostrum. Runing along both the dorsal and ventral sides of the rostrum are teeth, giving it the appearance of a double-edged saw.

Lateral to the rostrum are the ocular peduncles, upon which are situated the eyes, which jut out laterally from the head. Being compound eyes, they are composed of a large number of subunits, called ommatidia (Lockwood, 1968). Ventral to the eyes are the antennular penduncles (from which extends 2 pairs of antenullar flagella) and the antennal peduncles (extending from which is a pair of antennal flagella). The antennae serve in touch and chemoreception, whilst the antennules contain balance organs known as statocysts (Schram et al., 2010).  

figure image
Image 3 – Close-up of the eye of P. serrifer. (Image: Craig Regan, 2015)

The abdomen itself is divided into 5 sections known as the abdominal somites. Posterior to the 5th somite, is a modified somite which forms the tail-fan (Smaldon et al., 1993). The tail-fan consists of uropods (the medially situated endopod and the lateral exopod) and a spike-like telson.

figure image
Image 4 - The tail of P. serrifer. Note the spike-like telson
and the fan-like uropods. (Image: Craig Regan, 2015)

These, coupled with powerful abdominal muscles, allow the shrimp to produce quick bursts of speed to escape a threat, propelling themselves backwards through flicking of the tail (Schram et al., 2010). Video 4 shows this characteristic tail-flick in escaping an intruder. 

Video 4 - P. serrifer using tail-flick to escape a threat (Video: Craig Regan, 2015)

 On the posterior side of the abdomen are 5 pairs of pleopods. These are used for swimming, being leaf-like in structure (Smaldon et al., 1993). Observing the individuals clearly shows them being used in a fanning motion to enable the shrimp to swim forwards. Another use of the pleopods is for egg storage, which is a trait common to shrimp of the suborder Pleocyemata (Burkenroad, 1963).

figure image
Image 5 – Egg mass of P. serrifer. (Image: Craig Regan, 2015)
figure image
Image 6 – Single egg of P. serrifer, with H&E stain under
30x magnification. (Image: Craig Regan, 2015)

Internally, the gills and heart are located within the protection of the carapace, and link to an open circulatory system consisting of hemolymph (Schram et al.,2010). The nervous system is made up of a cerebral ganglion, from which branches the antennal, antennular and optic nerves, and connects to a ventral nerve cord (Schram et al., 2010). The nerve axons are surrounded by mulitlayered sheath membranes, similar in composition to the myelin sheaths of vertebrate nerves (Okamura et al., 1986). 

Figure 2
Figure 3
Figure 4
Figure 5
Figure 6


Shrimp, and Decapods in general, have a diverse range of sensory, respiratory, neural and osmoregulatory functions.

Respiration in Decapods is aided by the dorso-ventral pumping of the blade-like scaphognathites, causing a flow of water over the gills (Wilkins & McMahon,1972). Whilst the gills are the primary site of respiration, the pleopods have been shown to serve an auxiliary respiratory role (Torres et al., 1977). Just as the pleopods serve multiple functions, so too do to the gills themselves, which are also important in osmoregulation.

Whilst most saltwater crustaceans are osmoconformers, with isotonic hemolymph, they still have the need  for osmoregulation and so must expend energy in the maintenance of their internal fluids (Péqueux, 1995; Lockwood, 1968). This is primarily achieved by the gills, which serve in active, transepithelial ion transport (Freire atal., 2007).

Osmoregulation also plays an important role in growth during larval development. A notable study on the decapod Rhithropanopeus harrisii by Kalber & Costlow, (1966) revealed that growth of the larvae resulted from inflow of water due to hyper regulation of the hemolymph. This was timed to coincide with the increased permeability of the body wall that occurs during, and just after, the molt (Kalber &Costlow, 1966).

The nerves of shrimp are recognised as having very fast conduction speeds compared to other invertebrates, due largely to the presence of organised sheaths that surround their nerves (Heuser & Doggenweiler,1966). Simliar in composition to the myelin sheaths of vertebrates, they allow for saltatory conduction in the shrimp, albeit not quite as effectively (Heuser & Doggenweiler, 1966; Okamura et al.,1986).

Evolution and Systematics

The infrorder caridea, which consists of over 2800  species of shrimp, is one of the most diverse amongst the decapods (Schram et al., 2010). Within the carideans, the superfamily Palaemonoidea consists of 981 species, making them the most speciose of the carideans (De Grave and Franzen, 2011).

Despite the large numbers of shrimp that have been identified, historically speaking their phylogeny and systematics haven’t been extensively studied (De Grave, 2009). Early attempts at phylogeny were vague. Indeed Chace (1992) describes his review of caridean shrimps as “far-from-definitive” and is based primarily on variations in mouthparts and pereopods. Over-reliance on morphological differentiation is problematic especially in considering that many taxa, including the subfamily Palaemoninae,  have highly conservative morphological traits (Ashelby, 2012).

Despite this, throughout the years, attempts at phylogenetic classification of shrimp have mainly involved differentiation based on morphology (Holthuis, 1993, Chace 1992). It has only been quite recently that we have seen a shift towards reviewing molecular data in determining the phylogenetic relationships of shrimp (Kou, 2013). Studies on the development and structural evolution of the nervous system are also being used to gain insight into phylogenetic relationships (Harzsch & Glötzner, 2002). These more diverse approaches  have led to a surge in phylogenetic information over the last decade (DeGrave & Fransen, 2011).

Not only does this signify that more species have been classified and placed into their respective phylogenetic contexts, but that previous classifications have been changed and updated (Kou, 2013). For instance, current data characterises the superfamily Palaemonoidea as being comprised of 7 families, though this number has undergone various changes over the years (Chace, 1993; Martin & Davis, 2001; Kou, 2013).

Of these families, recent molecular data pertaining to a single mitochondrial gene and three nuclear genes, suggests family Palaemonidae to be polyphyletic (Kou, 2013). This is in contrast to the previous view proposed by Pereira (1997) that the Palaemonidae is monophyletic. Still, further molecular evidence is necessary in order to attain a more comprehensive phylogeny of the Carideans. 

Biogeographic Distribution

In Australia P. serrifer is found in estuarine areas amongst rocks and seagrass beds within Moreton bay and the Kimberley (Davie et al., 2002). Internationally, they are also found throughout the indo-west-pacific region, in parts of Korea (Yellow and Southern seas), China, Burma, Thailand, Taiwan, Japan, Indonesia and Vladivostok in Russia (Kim, 2008; Bruce, 1993).

figure image

Image 7 – Geographic distribution of P. serrifer in Australia. (Image: The Atlas of Living Australia,

Refer to Image 8, which shows the global distribution of seagrass beds throughout the world. Particularly note the orange area labelled number 5, which represents the indo-tropical pacific, within which falls the distribution of P. serrifer. 

figure image
Image 8 – Global seagrass distribution. (Image: Short et al., 2007).
Figure 7
Figure 9

Conservation and Threats

Due to a variety of, primarily anthropogenic, factors there is growing concern over the longterm survival and conservation of seagrass beds, with large-scale losses predicted worldwide (Duarte, 2002; Orth et al., 2006). With estuarine seagrass beds being a major habitat for P. serrifer, this amounts to a potentially serious threat for their survival as well. 

A billion or more people live within 50km of seagrass meadows around the world, and the loss in seagrasses is comparable to that of mangroves, coral reefs and tropical rainforests, making them one of the most threatened ecosystems on earth (Waycott et al., 2009). The dependence that conspicuous species such as dugongs and green sea turtles have for seagrass is well documented (Preen & Marsh, 1995; Aragones et al., 2000; Aragones et al., 2006; Orth et al., 2006). 

However, there is also a high importance to conserve common species, such as P. serrifer. Research has shown that even small declines in common species can significantly impact ecosystems (Gaston & Fuller, 2008). This highlights the urgency for conservation measures to be implemented. 

In this regard, organisations such as Seagrass Watch are great platforms to get involved in conservation. Founded in Australia in 1988, it is now a global program for assessment and monitoring of seagrass. A link to their website can be found here:

figure image
Image 9 - Seagrass watch
Figure 9


Allan, E. L.,Froneman, P. W., & Hodgson, A. N. (2006). Effects of temperature andsalinity on the standard metabolic rate (SMR) of the caridean shrimp Palaemon peringueyi. Journal of ExperimentalMarine Biology and Ecology, 337(1), 103-108. doi:

Aragones, L., & Marsh, H. (2000). Impact of dugong grazing andturtle cropping on tropical seagrass communities. Pacific conservation biology, 5(4), 277.

Aragones, L. V., Lawler, I. R., Foley, W. J., & Marsh, H.(2006). Dugong grazing and turtle cropping: grazing optimization in tropical seagrass systems? Oecologia, 149(4),635-647.

Ashelby, C. W., Page, T. J., De Grave, S., Hughes, J. M., &Johnson, M. L. (2012). Regional scale speciation reveals multiple invasions of freshwater in Palaemoninae (Decapoda). ZoologicaScripta, 41(3), 293-306.

Becker, J. H., & Grutter, A. S. (2004). Cleaner shrimp do clean. Coral Reefs, 23(4), 515-520. doi:10.1007/s00338-004-0429-3

Bell, S. S., & Coull, B. C. (1978). Field evidence that shrimp predation regulates meiofauna. Oecologia,35(2), 141-148. doi: 10.1007/bf00344727

Bruce, A. (1993). Caridean Shrimps (Crustacea: Decapoda) of the Albatross Philippine Expedition,1907-1910, Part 6: Superfamily Palaemonoidea.

Buric, M., Kouba, A., & Kozak, P. (2009). Chelae regeneration in European alien crayfish Orconectes limosus (Rafinesque 1817). Knowledge and Management of Aquatic Ecosystems(394-95), 10. doi: 10.1051/kmae/2009016

Burkenroad, M. (1963). The evolution of the Eucarida (Crustacea,Eumalacostraca), in relation to the fossil record. Tulane Studies in Geology, 2(1), 1-17.

Chace, F. A. (1992). On the classification of the Caridea (Decapoda). Crustaceana, 63(1), 70-80.

Davie, P. J., Wells, A., & Houston, W.(2002). Crustacea: Malacostraca: Phyllocarida, Hoplocarida, Eucarida: CSIRO PUBLISHING.

De Grave, S., Cai, Y., & Anker, A. (2008). Global diversity of shrimps (Crustacea:Decapoda: Caridea) in freshwater Freshwater Animal Diversity Assessment (pp. 287-293): Springer.

De Grave, S., & Fransen, C. (2011). Carideorum catalogus: the recent species of the dendrobranchiate, stenopodidean, procarididean and caridean shrimps (Crustacea: Decapoda): NCBNaturalis.

De Grave, S., Pentcheff, D. N., & Ahyong, S. T. (2009). A classification of living and fossil genera of decapod crustaceans. Raffles Bulletin of Zoology, 1-109.

De Vries, M. C., Rittschof, D., & Forward, R. B., Jr. (1991). Chemical Mediation of Larval Release Behaviors in the Crab Neopanope sayi. Biological Bulletin, 180(1), 1-11. doi:10.2307/1542424

Duarte, C. M. (2002). The future of seagrass meadows. Environmental Conservation, 29(2), 192-206.doi: 10.1017/s0376892902000127

Emmerson, W. (1985). Oxygen consumption in Palaemon pacificus (Stimpson) (Decapoda: Palaemonidae) in relation to temperature, size and season. Comparative Biochemistry and PhysiologyPart A: Physiology, 81(1), 71-78.

Feder, H. M. (1966). Cleaning symbiosis in the marine environment. Symbiosis, 1(S M), 327-380.

Forward, R. B., Rittschof, D., & De Vries, M. C. (1987). Peptide pheromones synchronize crustacean egg hatching and larval release. Chemical senses, 12(3), 491-498.

Frank, K. T., Petrie, B., Choi, J. S., & Leggett, W. C. (2005).Trophic cascades in a formerly cod-dominated ecosystem. Science, 308(5728), 1621-1623.

Freire, C. A., Onken, H., & McNamara, J. C. (2008). A structure-function analysis of ion transport in crustacean gills and excretory organs. Comparative Biochemistry andPhysiology a-Molecular & Integrative Physiology, 151(3), 272-304. doi:10.1016/j.cbpa.2007.05.008

Garm, A., & Hoeg, J. T. (2001). Function and functional groupings of the complex mouth apparatus of the squat lobsters Munida sarsi Huus and M. tenuimana G.O. Sars (Crustacea : Decapoda). Biological Bulletin, 200(3), 281-297. doi: 10.2307/1543510

Gaston, K. J., & Fuller, R. A. (2008). Commonness, population depletion and conservation biology. Trends in Ecology & Evolution, 23(1), 14-19. doi: 10.1016/j.tree.2007.11.001

Harzsch, S., & Glötzner, J. (2002). An immuno histochemical study of structure and development of the nervous system in the brine shrimp Artemiasalina Linnaeus, 1758 (Branchiopoda, Anostraca) with remarks on the evolutionof the arthropod brain. Arthropod Structure & Development, 30(4), 251-270. doi:

Heuser, J. E., & Doggenweiler.Cf. (1966). Fine structuralorganization of nerve fibers sheaths and glial cells in prawn Palaemonetes vulgaris. Journal of Cell Biology, 30(2),381-&. doi: 10.1083/jcb.30.2.381

Holthuis, L. B., Fransen, C., & van Achterberg, C. (1993). The recent genera of the Caridean and Stenopodidean shrimps (Crustacea, Decapoda): with an appendix on the order Amphionidacea: Nationaal Natuurhistorisch Museum.

Huni, A. A., & Aravindan, C. (1985). The effect of salinity on the oxygen consumption of two intertidal crustaceans. Comparative Biochemistry and Physiology Part A: Physiology, 81(4), 869-871.

Integrated Taxonomic Information System (ITIS) on-line database (2015).  Retrieved 19/05/2015, from

Ito, M., Watanabe, S., & Murano, M. (1991). Growth and reproduction of Palaemon pacificus and Palaemon serrifer. Nippon Suisan Gakkaishi, 57(7), 1229-1239.

Jones, M. (1981). Effect of temperature, season, and stage of lifecycle on salinity tolerance of the estuarine crab Helice crassa Dana(Grapsidae). Journal of Experimental Marine Biology and Ecology, 52(2), 271-282.

Kalber, F. A., Jr., & Costlow, J. D., Jr. (1966). The Ontogeny of Osmoregulation and Its Neurosecretory Control in the Decapod Crustacean,Rhithropanopeus harrisii (Gould). AmericanZoologist, 6(2), 221-229. doi: 10.2307/3881352

Kim, S. (2008). Growth, Fecundity, Egg Size And Recruitment Of Palaemon serrifer (Decapoda: Caridea: Palaemonidae). Journal of Ecology and Environment, 31(1), 9-15.

Kirkpatrick, K., & Jones, M. (1985). Salinity tolerance and osmoregulation of a prawn, Palaemon affinis Milne Edwards (Caridea:Palaemonidae). Journal of ExperimentalMarine Biology and Ecology, 93(1), 61-70.

Kou, Q., Li, X. Z., Chan, T. Y., Chu, K. H., & Gan, Z. B.(2013). Molecular phylogeny of the superfamily Palaemonoidea (Crustacea :Decapoda : Caridea) based on mitochondrial and nuclear DNA reveals discrepancies with the current classification. Invertebrate Systematics, 27(5), 502-514. doi: 10.1071/is13005

Lockwood, A. P. M. (1968). Aspects of the physiology of Crustacea: Oliver & Boyd Edinburgh.

Martin, J. W., & Davis, G. E. (2001). An updated classification of the recent Crustacea.

McCammon, A., Sikkel, P., & Nemeth, D. (2010). Effects of three Caribbean cleaner shrimps on ectoparasitic monogeneans in a semi-natural environment. Coral Reefs, 29(2),419-426.

McLaughlin, P. A. (1980). Comparative morphology of recent Crustacea: WH Freeman.

Nicolette, P. (1990). Symbiosis: nature in partnership. Blandford, London.

Okamura, N., Yamaguchi, H., Stoskopf, M., Kishimoto, Y., &Saida, T. (1986). Isolation and characterization of multilayered sheath membrane rich in glucocerebroside from shrimp ventral nerve. Journal of neurochemistry, 47(4),1111-1116.

Orth, R. J., Carruthers, T. J., Dennison, W. C., Duarte, C. M.,Fourqurean, J. W., Heck, K. L., . . . Olyarnik, S. (2006). A global crisis for seagrass ecosystems. Bioscience, 56(12),987-996.

Péqueux, A. (1995). Osmotic Regulation in Crustaceans. Journal of Crustacean Biology, 15(1),1-60. doi: 10.2307/1549010

Pereira, G. (1997). A cladistic analysis of the freshwater shrimps of the family Palaemonidae (Crustacea, Decapoda, Caridea). Acta Biologica Venezuelica, 17(Suppl), 1-69.

Preen, A., & Marsh, H. (1995). Response of dugongs to large-scale loss of seagrass from Hervey Bay, queensland, australia. Wildlife Research, 22(4), 507-519. doi:10.1071/wr9950507

Schram, F., Von Vaupel Klein, C., & Forest, J. (2010). Treatise on Zoology - Anatomy, Taxonomy, Biology. The Crustacea, Volume 9 Part A: Eucarida: Euphausiacea, Amphionidacea,and Decapoda (partim): Brill.

Short, F., Carruthers, T., Dennison, W., & Waycott, M. (2007).Global seagrass distribution and diversity: A bioregional model. Journal of Experimental Marine Biology and Ecology, 350(1–2), 3-20. doi:

Smaldon, G., Holthuis, L., Fransen, C., & Council, F. S. (1993).Coastal shrimps and prawns: Linnean Society of London and the Estuarine and Coastal Sciences Association.

Torres, J. J., Gluck, D., & Childress, J. (1977). Activity and physiological significance of the pleopods in the respiration of Callianassa californiensis (Dana)(Crustacea: Thalassinidea). Biological Bulletin, 134-146.

Waycott, M., Duarte, C. M., Carruthers, T. J. B., Orth, R. J.,Dennison, W. C., Olyarnik, S., . . . Williams, S. L. (2009). Accelerating loss of seagrasses across the globe threatens coastal ecosystems. Proceedings of the National Academy of Sciences of the United States of America, 106(30), 12377-12381. doi:10.1073/pnas.0905620106

Wilkens, J., & McMahon, B. (1972). Aspects of branchial irrigation in the lobster Homarus americanus I. Functional analysis of scaphognathite beat, water pressures and currents. Journal of Experimental Biology, 56(2), 469-479.

Ziegler, T. A., & Forward Jr, R. B. (2007a). Control of larval release in the Caribbean spiny lobster, Panulirus argus: role of chemical cues.Marine Biology, 152(3), 589-597.

Ziegler, T. A., & Forward Jr, R. B. (2007b). Larval release behaviors in the Caribbean spiny lobster, Panulirus argus: Role of peptide pheromones. Journal of chemical ecology,33(9), 1795-1805.