How to find and ID part 2
For certain species groups there are basic features you can hone in on to help you to ID. Here, we go through some major groups,
most of which are part of level 1 of Shoresearch Cymru training and which consist of commonly seen species and also some Invasive Non-Native Species.
Molluscs (marine snails)
Molluscs (marine snails etc) are a large grouping and animals from this group live in the deep ocean to the intertidal areas (as well as on land and in freshwater). The basic body plan is a head, a foot and then what’s called a “visceral mass” which is where the main body organs lie and this is covered by the “mantle” which gives rise to the
outer shell (some groups have no shell). Shelled molluscs in UK waters mostly consist of animals which make a cone-shaped or whorled shell (gastropods) and those which make two shells (bivalves). The basic body plan takes on many forms, so there are plenty of key areas on which to concentrate to help with ID.
Gastropods
The gastropods are the largest group with over 60,000 species globally. These animals have a well-developed head with eyes and sensory tentacles.
Looks: for Gastropods, keep an eye out for colour, patterns, ridges, shape of shell and opening (aperture), presence of groove for siphon, height of spire, number and size of whorls, size of animal, additional features such as extended area near opening.
Where: they will be found attached or sitting on rocks and algae, but also remember to search for these in crevices, buried and covered by other species. Also look at where you are on shore, as shore height can help to identify some gastropods.
Bivalves
Not many bivalves can be seen in the intertidal regions of rocky shores
Looks: on discovering any – look at size, shape, patterning, ridges and spines, colour, positioning of the “beak” and hinges.
Where: the majority bury themselves in sand and mud, but look in crevices and shallow sand.
Other molluscs
You will find molluscs such as chitons and sea slugs on your Shoresearches. There is no need, at this stage, to know species from each other, but do try to spot the different groups. Look out for where you found the animal, the size, colour, patterning.
Chitons are common, but commonly overlooked. Small and similar without getting close, ID to species will not be expected until beyond level 2 in Shoresearch training.
Looks: they are generally small, cryptic (hard to see against the background), so you will need to look for them often.
Where: chitons can be found under rocks.
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Sea slugs are molluscs mostly with no shell and instead have all sorts of protuberances such as gills, tentacles for smell, sight etc we can use for ID. Note, many sea slugs are very small and identifying them will be beyond Level 2 of Shoresearch training. However, there are larger individuals which might be seen and knowing what to focus on helps to ID.
Looks: look for size, shape, colour, patterning, number and shape of “tentacles” and other protuberances etc,
Where: under rocks, on algae, sides of rockpool. Ideally, an understanding of the species on which it might be feeding, will help too, as many are highly specialised feeders.
Alternative factoids
Want to get to know our molluscs a bit more? This section will not appear in the quiz.
- Most UK marine molluscs with coiled shells, coil in a clockwise direction, producing an opening on the righthand side as you look at it. There are molluscs which like to do things differently and coil in completed the opposite way, becoming left-handed. This has a huge affect on the animal’s ability to reproduce and they can only do so if they find another left-handed member of the same species – a very rare chance, indeed.
- Some bivalves can use their syphon to “hoover” the surface of the sand for food and you can see the marks, which look a bit like bird footprints.
- Some gastropods have a “door”, called an operculum, they shut behind themselves when they retreat into their shell to hide, or stay moist when the tide goes out.
- A scientific paper in 2015 reported findings that the limpet’s teeth had overtaken spider silk as the strongest biological substance known. If you’re still you might be able to hear them grazing on the rock, when you’re out too!
Crustaceans (crabs, prawns etc)
Almost all Crustaceans are marine animals. In British and Irish waters there are over 2,000 species. Their body plans is of segmented body areas and limbs and a hard exoskeleton made of chitin and calcium carbonate (which they have to moult in order to grow). Again, this group is very diverse, but this summary of what to look for might help you get to a grouping, at least.
The segmented body of a crustacean consists of head, thorax, abdomen (with a tail area) which are sometimes fused or folded; antennae and feeding appendages on the head and sometimes upper thorax as well as other appendages on the rest of the thorax and abdomen, which form legs in some species, or sometimes claws etc.
crabs/crancod
Crabs, although common around our coasts are not well known in terms of how their populations are doing and how species are moving around our coasts. We have 60 species of crab in the UK.
Looks: true crabs have 5 pairs of limbs (the claws being one of the pairs) and a central body area covered by the carapace. Look for size, shape of the carapace/pincers, spines, patterning, ridges, colour, paddle-shaped back leg tips.
Where: you will find crabs all over the shore. Many upper shores, especially with pebble, silt and rocks, are safety for some exceptionally small crabs. Larger adults can be found from midshore down, mostly, in rockpools, crevices, under weed and rocks, buried in the substrate, many moulting or mating.
crab-type animals/anifeiliaid fel crancod
Animals called crabs, but which are not true crabs, differ in number of visible appendages and in some, body shape and this can point to ID. However, both the groups mentioned here, the porcelain crabs and hermit crabs can be fairly obvious to spot based on how they live. There are 18 species of hermit crabs, so getting to species is difficult, but a close-up of the claws and head might help to secure a closer ID.
Looks: 4 clearly seen pairs of limbs, carapace shape, pincer size, length and also difference between the pair (and which side is largest in disparity), colour, hairs, tubercles/spines.
Where: porcelain crabs are most often found underneath rocks and attached to the underside of rocks. They can be found elsewhere also, so use the tips on how they look to help ID. Hermit crabs all use mollusc shells to protect their abdomen, found in rockpools and low tide area, they will stop and hide in their shell, if disturbed, but often don’t take long to move. Some will bury themselves.
prawns and shrimp/corgimychiaid a berdys
These crustaceans have a longer body (some extremely long) and a more obvious tail area. There are a few different species of prawns and shrimp and within these groups ID is difficult, but you can try to decipher between the groups by looking at certain areas of the body which can differ between them. This group also includes opossum, chamaeleon and skeleton shrimp.
Looks: to ID to group, look for colour, patterning, size, body width, body compression (slightly flattened from side to side or upper to under surface), limb size, angled back, a great area if you can see/photograph it is the pointed part in between the eyes – in prawns this “rostrum” is generally longer.
Where: rockpools, sandpools, on algae, hidden at rock edges, crevices
Other crustaceans
There are plenty more in the crustacean group you might come across, but might need extra work to ID, or they are less commonly/likely to be seen in the intertidal zone. So below is just an introduction to know to look out for them, mostly.
Squat lobsters are a group which tends to be seen less on a Shoresearch survey, but good to be prepared. They are varied in size (overall length from around 1cm to 10cm), elongated and have the tail tucked underneath. They can be various colours with striped patterning and their claws are long and held in front.
Springtails have been moved out of the Insect grouping and are thought to be Crustacean relatives, so we’ll mention them here. They are very easily found and ID’d when you know where to look. Either walking on rocks amongst barnacles or floating on the surface of small patches of water, these are tiny, blue-black, elongate creatures.
Barnacles – sometimes, if they’re growing in sheltered areas with little rocky substrate, they can compete with each other and finding the ID features can become tricky. To ID in general, you will need to make note of the number of outer plates which form the shell, the shape of the opening, any patterns, overall shape and perhaps the shore height on which you found it.
Isopods and Amphipods – you will see these on shore, but they are tricky to ID, so an idea of what you’ve seen is all that is asked for the first few levels of Shoresearch Cymru training. Both can be found high up the shore on rocks, all the way to well below the low tide point. They can often be hidden under weed, in sand, in crevices etc
Isopods are flattened dorso-ventrally like woodlice and include animals like sea slaters.
Amphipods are flattened laterally and include sand hoppers and ghost shrimp.
Alternative factoids
Here are a few more bits of information you may not know about our crustaceans. This section will not appear in the quiz.
- There are over 30,000 crustacean species globally.
- Darwin spent time (> 8 yrs) studying barnacles, which helped him as he formulated his Theory of Evolution.
- Lobsters are nocturnal
- Many female crabs use their large tail (dome-shaped with usually 5 segments) to hold fertilised eggs – the female is called “berried”. Males have a more triangular tail usually with 3 segments.
- The Chamaeleon shrimp changes colour depending on whereabouts it’s living.
Algae
Algae is an enormous group, but luckily we can reduce this general description to those likely to be found in the intertidal region. Even then, there are groups of algae which take a long time and expertise to identify. Those are mostly from two groups the green algae and the red algae.
Algae takes the ecological place of plants in the sea (the green and reds are classed as plants); it photosynthesises, forms structures others attach to or take shelter within and provides food for some.
Because it photosynthesises it needs light and can only be found in the upper layers.
Many forms consist of an attachment (holdfast), a stipe (like a stem) and frond (like a leaf), many have rounded floats or bladders, some branch, have frilling or spines. Although, not part of Shoresearch, it is important to remember that phytoplankton (the microscopic, algal part of plankton) is a large part of this grouping.
brown algae
These include two groups which form the bulk of the identifiable algae on Shoresearches and include the wracks (closer look in Lesson 2). Brown algae are thick, often large and sturdy species. Seen lying out of water, often the features can be clearly seen to help with ID. These species use additional photosynthetic pigments, including Fucoxanthin, to collect energy from sunlight in reduced light conditions and which mask the green of the Chlorophyll.
Looks: length of frond, frills, holdfast, bladders, midrib and receptacles
Where: on rocks, in rockpools, crevices
green algae
Green seaweeds like shallow water, some are seasonal and many are quite delicate plants. It is argued that the larger forms in this grouping sit within the Plant Kingdom rather than algae. They include much of the vast and important oceanic food sources, phytoplankton. They use Chlorophyll a as their primary photosynthetic pigment.
Looks: shape, size, colour, texture
Where: on rocks, in rockpools, on shells
Alternative factoids
laver/lafwr (Porphyra umbilicalis) ©NWWT
Why not learn a bit more about Marine algae. This section will not appear in the quiz.
- some algae can be found in household products such as ice cream and toothpaste and food colourant in margarine and salad dressings.
- some kelp species can grow as much as half a metre a day
- green algae gave rise to all land plants
- seaweeds can assimilate minerals straight from the sea (a highly energy-demanding reaction)
- the red seaweed grouping Porphyra, which is used to make Sushi. is also the algae used to make laver bread.
- about half the World’s oxygen is produced by phytoplankton
Animal colonies
Many animal groups have some or all species within them forming colonies. The majority are attached to something sturdy and many can challenge your view of what an animal looks like.
Some colonies are so connected that each individual cannot live independently, some share important organs and systems for life. Many of these are only able to be identified to species by using a microscope.
Because these come from a wide array of animal groupings there is much to focus on to help you identify what you’re looking at.
The majority of these groups are filter-feeders, so look for syphons (whereabouts on the colony, patterning within the colony) and pores. Also take note of colour, structure, any outgrowths, jellylike outer coating, branching pattern, how they’re growing, shape of individual polyp housing (needs an eye lens).
hydroids and bryozoans
Looking very similar, these animal colonies can be tricky to learn to ID, even to being a member of the Phylum Bryozoa (sea mats and mosses) or Class Hydrozoa (sea firs). They can be very common on algae and rocks, being called animal turf when this happens.
Looks: encrusting on algae/shells/rocks, branching architecture, overall growth form, individual polyp shape, shape of breeding cells if present.
Where: attached to algae, rocks, shells, each other.
sea squirts/chwistrellau môr
These animals have a sac-like body with in and out syphons they use to feed with. The can be organised into shapes when forming a colony and look gelatinous. Found attached to hard substrate, they are often seen out of water on a Shoresearch survey. So, it’s a good idea to re-submerge to see the features to use for identifying.
Looks: syphon layout, colour, patterning, presence of a stalk
Where: low shore on rocks, under overhangs, in crevices
sponges/sbyngau
Growing in many different forms, sponges are attached to hard surfaces, take in water through pores which may be microscopic, but often release water through larger holes (excurrent pores), which might be visible and can be an ID feature. Many species can only be identified by using a microscope, but some can be ID’d by where and how they grow.
Looks: firmness, doesn’t change shape when submersed, growth look (flat, rounded, branched), colour, excurrent pores
Where: low shore under rocks, on rocks, under overhangs, in crevices.
Alternative factoids
Here are a few more bits of information you might find interesting about these animal colonies. This section will not appear in the quiz.
- There may be close to 15,000 species of sponge globally.
- Sea squirts are our closest invertebrate relative (they are part of the Chordata Phylum)
- Sea squirts, squirt water out, when disturbed
- Hydroids are related to jellies and anemones and therefore have stinging cells to catch their prey.
- Sponges are old in evolutionary terms, they once were the main animal group on the planet and considerable time passed before evolution “kicked in” to create a greater diversity (the Cambrian explosion).
- Bryozoan means Bryo – mossy and Zoa – animals
The next section is the quiz. Click to begin the quiz, the questions will appear below. For the fill-in-the-gaps questions, make sure you spell the same way as the word/phrase in the list, but don’t worry about using capitals or not. If you get any one question wrong within each quiz page, the you will be marked as wrong for the whole page. Answers will appear one you’ve finished each question.
You will be tested on what you’ve learnt so far using the reading and video info. Don’t worry too much, as once you’ve been out on the shore, the ID features you’ve learnt about will make more sense and after a couple of visits you should feel more confident about your ID.
Good luck!