Taxonomy

Since the last two centuries, the classification of decapods, particularly of crabs have passed through a series of changes. Earlier, Latreille (1802) divided Decapoda into the long-tailed Macrura and short-tailed Brachyura. Later, Milne Edwards (1834) created a third decapodan division called the Anomura. Milne Edwards then divided brachyuran crabs into 4 groups

1. Oxyrhynques (spider crabs),

2. Cyclometopes ( round fronted crabs )

3. Catometopes (square fronted crabs)

4. Oxystomes (sharp fronted crabs).

De Haan (1833-49), based on mouth parts, regrouped the brachyurans into 2 main divisions Oxystomata and Brachygnatha. Later Dana (1852 a, b, c) modified the scheme of Milne Edwards and classified Brachyura into 5 sub-tribes namely

1. Maioidea

2. Cancroidea

3. Corystoidea

4. Graposidea

5. Leucosoiidea.

Then Miers (1886) grouped Brachyura into 4 sub-tribes as

1. Oxystomata or Leucosiidea

2. Oxyrhyncha or Maioidea

3. Cyclometopa or Cancroidea

4. Catometopa or Ocypodiidea. Alcock (1895-1900) followed the above classification with slight modifications. In the meantime Bouvier (1896) classified Brachyura into 5 tribes as

1. Dromiacea

2. Oxystomata

3. Corystoidea

4. Brachyrhyncha

5. Oxyrhyncha.

Later Borradaile (1907) classified the Tribe Brachyura into 3 sub-tribes as

1. Dromiacea

2. Brachygnatha

3. Oxystomata

Borradaile's general scheme had been widely accepted by zoologists and Balss (1957) followed the same with slight modifications. In his classification, the Tribe Brachyura had 4 sub-tribes as

1. Dromiacea

2. Oxystomata

3. Brachygnatha

4. Hapalocarcinoidea.

Glaessner's (1969) classification included 5 sections namely

1. Dromiacea

2. Oxystomata

3. Oxyrhyncha

4. Cancridea

5. Brachyrhyncha.

Later Sakai (1976) classified Brachyura into 7 sub-sections as

1. Dromiacea

2. Gymnopleura

3. Oxystomata

4. Oxyrhyncha

5. Corystoidea

6. Brachyrhyncha

7. Hapalocarcinidea.

Guinot (1977, 1978) proposed a new classification of adult Brachyura based primarily on the position of female and male genital openings. In her classification, she proposed:

  • Podotremata: Families in which both female and male openings are coxal.
  • Heterotremata: Families in which the female genital openings are all sternal, whereas at least some representatives have the male openings coxal.
  • Thoracotremata: Families in which both the female and male openings are always sternal.

Rice (1980) proposed brachyuran classification based on larval characteristics. Nowadays, Guinot's classification is widely followed and it received much support from Rice (1980) also. In the present study, brachyuran crabs of the west coast, India are arranged as per the classification of Guinot ( 1977, 1978).