This document provides information on the diversity of finfish and shellfish species around the world and in India. It discusses that there are over 33,000 known fish species worldwide, categorized as finfish which have fins and gills, and shellfish which have gills and a shell/exoskeleton like crustaceans and mollusks. It also provides details on the classification and types of various crustacean and mollusk species.

1. Fin Fishes and Shell Fishes Diversity of
the world and India
By
BHUKYA BHASKAR
Fisheries

2. Introduction
• Fish is a cold-blooded aquatic organism that breathes with gills and swims with fins; they are
categorized as Finfish and Shellfish.
• Finfish are cold-blooded aquatic vertebrates that have gills, fins with rays, and scales
covering the body.
• Shellfish are cold-blooded aquatic invertebrate that have gills, various types of locomotory
organs and a shell/ exoskeleton covering the body. They include crustaceans and mollusc.
• The term ‘fish’ includes hagfishes, lampreys, chondrichthyans (sharks, rays, chimaeras),
actinopterygians (ray-finned fishes), actinistians (coelacanths and lungfishes).
• Fins are distinctive anatomical features composed of bony spines or rays protruding from the
body of Actinopterygii and Chondrichthyes fishes which are called as fin fishes.
• About 33,230 known fish Species reported world wide as per Fishbase, covers species-group
taxa; 59 species have 95 subspecies 33,125 species.
• As per recent order list in total count of Fish Genera: 5198
• Total count of Fish Species: 35332.
• Shellfish are a group of aquatic invertebrate animals that are either mollusks, crustaceans,
or echinoderms.
• Types of Shellfish • Crustaceans: Prawns, Shrimps, Crabs, Lobsters, Crayfishes, etc. •
Molluscs: Gastropods (snails), Pelecypods or Bivalves (clams, mussels, oysters) and
Cephalopods (squids, cuttlefish, octopus).
• Mollusks are shelled animals like oysters and mussels, crustaceans are animals with an
exoskeleton like shrimp, prawns and lobsters, and echinoderms have a spiny skin, like sea
urchins and sea cucumbers.

3. • Cluster analysis of
extant of fishes as
determined by
evidence of
common ancestry
or by the
appearance of
fossil forms.

4. Sl No
Name of the Fish
Order
No of
families
No of
genera
No of
species
Sl No
Name of the Fish
Order
No of
families
No of
genera
No of
species
1 Myxiniformes 1 6 88
2 Petromyzontiformes 3 10 48
3 Hexanchiformes 2 4 7
4 Heterodontiformes 1 1 9
5 Orectolobiformes 7 13 45
6 Lamniformes 8 10 16
7 Carcharhiniformes 11 52 304
8 Squaliformes 6 22 142
9 Echinorhiniformes 1 1 2
10 Pristiophoriformes 1 2 10
11 Squatiniformes 1 1 26
12 Torpediniformes 5 16 73
13 Rhinopristiformes 5 13 76
14 Rajiformes 4 39 311
15 Myliobatiformes 12 38 257
16 Chimaeriformes 3 6 55
17 Polypteriformes 1 2 14
18 Acipenseriformes 2 6 27
19 Lepisosteiformes 1 2 7
20 Amiiformes 1 1 1
21 Elopiformes 2 2 9
22 Albuliformes 1 3 13
23 Notacanthiformes 2 7 28
24 Anguilliformes 16 155 944
25 Saccopharyngiformes 5 5 28
26 Hiodontiformes 1 1 2
27 Osteoglossiformes 6 31 255
28 Clupeiformes 10 85 429
29 Alepocephaliformes 2 33 143
30 Gonorynchiformes 4 7 38
31 Cypriniformes 23 496 4579
32 Characiformes 24 287 2231
33 Gymnotiformes 5 34 246
34 Siluriformes 39 507 3922
35 Lepidogalaxiiformes 1 1 1
36 Argentiniformes 4 22 94
37 Galaxiiformes 1 7 66
38 Esociformes 2 4 14
39 Salmoniformes 1 11 226
40 Osmeriformes 4 17 42
41 Stomiiformes 4 52 435
42 Ateleopodiformes 1 4 13
43 Aulopiformes 17 46 285
44 Myctophiformes 2 37 255
45 Lampriformes 6 11 23
46 Percopsiformes 3 7 10
47 Zeiformes 6 16 33
48 Stylephoriformes 1 1 1
49 Gadiformes 17 83 629
50 Polymixiiformes 1 1 10

5. Sl No
Name of the Fish
Order
No of
families
No of
genera
No of
species
Sl No
Name of the Fish
Order
No of
families
No of
genera
No of
species
51 Beryciformes 8 31 120
52 Trachichthyiformes 5 20 68
53 Holocentriformes 1 8 90
54 Ophidiiformes 4 121 555
55 Batrachoidiformes 1 23 83
56 Scombriformes 16 76 279
57 Syngnathiformes 5 67 329
58 Dactylopteriformes 2 4 13
59 Callionymiformes 2 18 211
60 Mulliformes 1 6 100
61 Kurtiformes 2 40 360
62 Gobiiformes 13 315 2292
63 Synbranchiformes 4 14 126
64 Anabantiformes 8 28 262
65 Carangaria/misc 8 17 108
66 Pleuronectiformes 16 129 820
67 Carangiformes 7 43 172
68 Cichliformes 2 243 1780
69 Atheriniformes 11 52 380
70 Cyprinodontiformes 14 141 1399
71 Beloniformes 6 34 286
72 Mugiliformes 1 26 78
73 Gobiesociformes 1 52 181
74 Blenniiformes 6 153 939
75 Ovalentaria/misc 8 94 803
76 Acanthuriformes 13 55 449
77 Lophiiformes 21 74 390
78 Tetraodontiformes 10 106 446
79 Centrarchiformes 21 78 297
80 Acropomatiformes 21 60 297
81 Eupercaria/misc 22 281 1764
82 Perciformes/Percoidei 3 14 249
83 Perciformes/Zoarcoidei 14 108 410
84 Perciformes/Bembropoidei 1 2 23
85 Perciformes/Percophoidei 1 1 1
86
Perciformes/Notothenioide
i
8 46 159
87
Perciformes/Uranoscopoid
ei
5 24 186
88 Perciformes/Serranoidei 6 74 587
89 Perciformes/Scorpaenoidei 21 133 829
90
Perciformes/Gasterosteoid
ei
3 8 23
91 Perciformes/Cottoidei 10 157 858
92 Coelacanthiformes 1 1 2
93 Ceratodontiformes 3 3 6
Total 623 5198 35332

6. Crustaceans
• Crustaceans are some of the most important
marine life to humans—crabs, lobsters, and shrimp
are widely fished and consumed around the world.
• There are more than 52,000 species of
crustaceans in the world, which include popular
marine animals like lobsters, crabs, shrimp,
crayfish, and barnacles
• There are more than 52,000 species of crustaceans
in the world, which include popular marine
animals like lobsters, crabs, shrimp, crayfish, and
barnacles.
• Smaller crustaceans breathe through their bodies
and larger ones breathe through gills. Most
crustaceans are dioecious, meaning individuals are
male or female.
• All crustaceans have a hard exoskeleton which
protects the animal from predators and prevents
water loss. However, exoskeletons do not grow as
the animal inside them grows, so crustaceans are
forced to molt as they grow larger.
• The molting process takes between a few minutes
to several hours.
• During molting, a soft exoskeleton forms
underneath the old one and the old exoskeleton is
shed. Since the new exoskeleton is soft, this is a
vulnerable time for the crustacean until the new
exoskeleton hardens.
• After molting, crustaceans typically expand their
bodies almost immediately, increasing by 40–80%.
Most crustaceans reproduce sexually with a
separate male and female
• Crustaceans include all the animals of the phylum
Arthropoda Crustacea; the word comes from the
Latin crusta, which means shell.
• Crustaceans are a very diverse group of
invertebrate animals which includes active animals
such as the crabs, lobsters, shrimp, krill, copepods,
amphipods, and more sessile creatures like
barnacles. Arthropoda is the largest phylum of
Animal Kingdom.
• It includes about 11,340,000 species in all
habitats.
• This constitutes about 83% of all the known animal
species on earth.
• Arthropoda includes spider, scorpions, prawns,
crabs, millipedes, centipedes, and many other
insects.
• Arthropoda is characterized by heteronomous
metamerism, chitinous exoskeleton, and joined
appendages.
• The evolutionary acquisition of these traits is
known as arthropodization.
• In very small crustaceans, exchange of the
respiratory gases occurs through the general body
surface.
• Large aquatic arthropods respire through gills and
book gills, whereas terrestrial forms respire
through trachea and book lungs.

7. Classification of the Crustacea (Ref: Siveter et al, 1991)

8. Mollusca
• Mollusca is the second
largest phylum of invertebrate animals,
after the Arthropoda; members are known
as molluscs or mollusks[a] (/ˈmɒləsk/).
• Around 85,000 extant species of molluscs
are recognized.
• Mollusca is one of the most diverse groups
of animals on the planet, with at least
50,000 living species (and more likely
around 200,000).
• Currently 46,000 valid species of recent
marine molluscs are known, which is
increasing by a yearly increment of 443
new species.
• Rosenberg (2014) estimated that 43,600 ±
900 valid species had been described;
WoRMS now catalogues a little over
46,000 species (WoRMS 2016),
• Scientific classification
• Domain:EukaryotaKingdom
:AnimaliaSubkingdom:Eum
etazoaClade:ParaHoxozoaCl
ade:BilateriaClade:Nephroz
oa(unranked):Protostomia(
unranked):SpiraliaSuperph
ylum:LophotrochozoaPhylu
m:Mollusca
Linnaeus, 1758Classes

9. Echinodermata
• An echinoderm is any member of
the phylum Echinodermata (/ɪˌkaɪnoʊˈdɜːr
mətə/).
• The adults are recognisable by their
(usually five-point) radial symmetry, and
include starfish, brittle stars, sea
urchins, sand dollars, and sea cucumbers,
as well as the sea lilies or "stone lilies“
• The phylum contains about 7,000
living species, making it the second-largest
grouping of deuterostomes, after
the chordates.
• Echinoderms are the largest entirely
marine phylum.
• All echinoderms are marine, but they are found
in habitats ranging from shallow intertidal areas
to abyssal depths.
• Two main subdivisions are traditionally
recognised: the more
familiar motile Eleutherozoa, which
encompasses the Asteroidea (starfish, with
some 1,745 species), Ophiuroidea (brittle stars,
with around 2,300 species), Echinoidea (sea
urchins and sand dollars, with some 900
species) and Holothuroidea (sea cucumbers,
with about 1,430 species); and the Pelmatozoa,
some of which are sessile while others are
motile.
• These consist of the Crinoidea (feather
stars and sea lilies, with around 580 species)
and the extinct blastoids and Paracrinoids

10. Cnidaria
• Cnidaria (/nɪˈdɛəriə, naɪ-/) is a phylum under
kingdom Animalia containing over 11,000 species
of aquatic animals found both
in freshwater and marine environments,
predominantly the latter.
• Their distinguishing feature is cnidocytes,
specialized cells that they use mainly for capturing
prey.
• Their bodies consist of mesoglea, a non-living jelly-
like substance, sandwiched between two layers
of epithelium that are mostly one cell thick.
• Cnidarians mostly have two basic body forms:
swimming medusae and sessile polyps, both of
which are radially symmetrical with mouths
surrounded by tentacles that bear cnidocytes.
• Both forms have a single orifice and body cavity
that are used for digestion and respiration.
• Many cnidarian species produce colonies that are
single organisms composed of medusa-like
or polyp-like zooids, or both (hence they
are trimorphic).
• Cnidarians' activities are coordinated by a
decentralized nerve net and simple receptors.
• Several free-swimming species
of Cubozoa and Scyphozoa possess balance-
sensing statocysts, and some have simple eyes.
• Not all cnidarians reproduce sexually, but many
species have complex life cycles of asexual polyp
stages and sexual medusae stages.
• Cnidarians were formerly grouped
with ctenophores in the phylum Coelenterata, but
increasing awareness of their differences caused
them to be placed in separate phyla.
• Cnidarians are classified into four main groups: the
almost wholly sessile Anthozoa (sea
anemones, corals, sea pens);
swimming Scyphozoa (jellyfish); Cubozoa (box
jellies); and Hydrozoa (a diverse group that includes
all the freshwater cnidarians as well as many marine
forms, and has both sessile members, such
as Hydra, and colonial swimmers, such as
the Portuguese man o' war)
• Scientific classification
Domain:EukaryotaKingdom:Animalia
Subkingdom:Eumetazoa
Clade:ParaHoxozoa
Phylum:Cnidaria Hatschek, 1888

11. Porifera
• Sponges, the members of
the phylum Porifera meaning 'pore
bearer'), are a basal animal clade as a
sister of the diploblasts.
• They are multicellular organisms that
have bodies full of pores and channels
allowing water to circulate through
them, consisting of jelly
like mesohyl sandwiched between two
thin layers of cells.
• approximately 5,000–10,000 known
species of sponges feed
on bacteria and other microscopic
food in the water, some
host photosynthesizing microorganis
ms as endosymbionts, and these
alliances often produce more food
and oxygen than they consume.
• Scientific classification
Domain:Eukaryota
Kingdom:Animalia
Phylum:Porifera
Grant, 1836
• ClassesCalcarea
1. Demospongiae
2. Hexactinellida
3. Homoscleromorpha
4. Archaeocyatha
5. Heteractinida" (paraphyletic)
6. Stromatoporoidea

12. Indian fish diversity
• Russell made the first systematic study of the Indian fish fauna
from 1785 to 1789 AD.
• Sir Francis Day studied the systematics of Indian fishes for over 20
years and listed 351 genera and 1418 species of marine, brackish
water and freshwater fishes in 1868.
• 2,508 species of native finfish have been recorded, of which 1,518
species are from the marine environment, 113 from brackish
waters and 877 are from freshwater habitats. In addition, 291
exotic fish species also occur in India
• NBFGR Developed database on fish diversity of India containing
information about 2953 finfish species.
• India is home to more than 10% of the global fish biodiversity and
is one of the 17-mega biodiversity rich countries.
• In India, out of 877 native freshwater fish species, about 450 are
Small Indigenous Fish Species (SIFS).
• The country is bestowed with vast and varied coldwater/hill
fishery resources which are spread over the Himalayan and
peninsular regions as upland rivers, streams, high and low altitude
natural lakes and reservoirs. There are around 8,243 km long
streams and rivers, 20,500 ha natural lakes, 50,000 ha of
reservoirs, both natural and manmade, and 2500 ha brackish
water lakes in the high altitude (Mahanta & Sarma, 2010).
• The coldwater fisheries harbour 258 species belonging to 21
families and 76 genera. Out of these, the maximum of 255 species
are recorded from North-East Himalaya, 203 from the west and
central Himalaya and 91 from the Deccan plateau
• More than 117 species of shrimps, 17 species of
lobsters and around 700 species of crabs are
found to inhabit mostly marine and estuarine
areas in the country, of which around 150
species contribute to commercial catches.
• Around 80% of the Crustacean landings are
from the West Coast while only about 20% are
from the East Coast. Maharashtra followed by
Gujarat top in Crustacean fisheries production.
• About 3270 species have been reported from
India belonging to 220 families and 591 genera.
• Among these the bivalves are the most diverse
(1100 species), followed by cephalopods (210
species), gastropods (190 species),
polyplacophores (41 species) and scaphopods
(20 species
• Nearly 652 species of marine bivalves are
reported from India, of which 88 species are
endemic to Indian waters

13. Source: CMFRI

17. References
• https://fishbase.de/home.htm
• Footnote: Minelli makes a definitive point about ranking as being an arbitrary and subjective decision: "The main difficulty
resides in determining whether two clades in distant parts of the phylogenetic tree deserve [being] acknowledged [at] the same
rank or not." (Minelli, 2009:11). "But all this amounts to counting fruit by adding apples and cherries." (Minelli, 2009:12). In
other words, if counting orders, families, and genera in a narrow context (e.g., number of genera in subfamilies of the same
family) may be locally sensible (within a phylogenetic tree / classification), counting families across classes or orders is most
often irrelevant: for instance, why assigning clown-fishes only the subfamily rank (Pomacentridae: Amphiprioninae) while the
Moorish idol has a family of its own (Zanclidae), and not a subfamily in Acanthuridae?
• Bailly, N., 2010. Why there may be discrepancies in the assessment of scientific names between the Catalog of Fishes and
FishBase. Electronic document. [Version 2, May 6th, 2010]. //www.fishbase.org/Nomenclature/FBCofFNames.php
• Eschmeyer, W.N. (ed.). Catalog of Fishes. Successive updated online
versions http://research.calacademy.org/research/Ichthyology/catalog/fishcatmain.asp.
• Eschmeyer, W.N. and J.D. Fong. Species of Fishes by family/subfamily. Successive updated online
versions. http://research.calacademy.org/research/ichthyology/catalog/SpeciesByFamily.asp.
• Minelli, A., 2009. Perspectives in animal phylogeny. Oxford University Press.
• Nelson, J.S., 2006. Fishes of the World. 4th ed. Hoboken (New Jersey, USA): John Wiley & Sons. xix+601 p. [Ref. 58010]
• Wiley, E.O. and G.D. Johnson, 2010. pp. 123-182. A teleost classification based on monophyletic groups. In: Origin and
phylogenetic interrelationships of Teleosts. Honoring Gloria Arratia. Proceedings of the International Symposium at the ASIH
Annual Meeting in St. Louis, Missouri, 2007. (Nelson et al., eds). München (Germany): Verlag Dr. Friedrich Pfeil. [Ref. 84927]
• Crustacea Edited by Genaro Diarte-Plata and Ruth Escamilla-Montes; https://www.intechopen.com/chapters/70062
• Siveter DJ, Vannier JM, Palmer D. Silurian Myodocopes: Pioneer pelagic ostracods and the chronology of an ecological shift.
Journal of Micropalaeontology. UK: University of Leicester; 1991;10(2):151-173
• Philippe Bouchet, Sophie Bary, Virginie Héros & Gilberto Marani 2016. How many species of molluscs are there in the world’s
oceans, and who is going to describe them?
• https://en.wikipedia.org/wiki/Echinoderm
• https://en.wikipedia.org/wiki/Cnidaria
• https://en.wikipedia.org/wiki/Sponge
• http://eprints.cmfri.org.in/12911/
• https://www.nbfgr.res.in/en/page/salient-achievements
• https://www.google.com/search?sca_esv=565929224&sxsrf=AM9HkKmOUsuodA_yM4cio7ISVy6Q_bViLw:1694875661160&q=
marine+fishes+groups&tbm=isch&source=lnms&sa=X&ved=2ahUKEwjt3uLtr6-
BAxWkSmwGHU9hCuQQ0pQJegQIDBAB&biw=1600&bih=751&dpr=1