Research Article |
Corresponding author: Tung-Wei Shih ( stw@mail.nmmst.gov.tw ) Academic editor: Sammy De Grave
© 2017 Guo-Chen Jiang, Tin-Yam Chan, Tung-Wei Shih.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Jiang G-C, Chan T-Y, Shih T-W (2017) Larval development to the first eighth zoeal stages in the deep-sea caridean shrimp Plesionika grandis Doflein, 1902 (Crustacea, Decapoda, Pandalidae). ZooKeys 719: 23-44. https://doi.org/10.3897/zookeys.719.20916
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The larvae of the deep-sea pandalid shrimp Plesionika grandis Doflein, 1902 were successfully reared in the laboratory for the first time. The larvae reached the eighth zoeal stage in 36 days, both of which are longest records for the genus. Early larval stages of P. grandis bear the general characters of pandalid shrimps and differ from the other two species of Plesionika with larval morphology known in the number of spines on the anteroventral margin of carapace, number of tubercles on antennule, endopod segmentation in antenna, and third maxilliped setation. Although members in Plesionika are often separated into species groups, members of the same species group do not necessarily have similar early larval morphology. Since the zoea VIII of P. grandis still lacks pleopods and fifth pereiopod, this shrimp likely has at least 12 zoeal stages and a larval development of 120 days.
Deep-sea, larval development, Pandalidae , Plesionika , shrimps, zoea
The predominant deep-sea shrimp genus Plesionika Bate, 1888 is the most diverse genus in the caridean family Pandalidae Haworth, 1825, being represented by 93 species (
Plesionika grandis Doflein, 1902 is a widely distributed species in the Indo-West Pacific from Japan to NE Australia and Madagascar at depths of 110–375 m (
The ovigerous female of P. grandis was collected by a commercial trawler at depths of 220 m off northeastern Taiwan (24°52.352'N; 121°58.010'E). The berried female was reared in a 100 L aquarium and raised in sea water (salinity of 35) at 14 ± 1°C. Once the eggs hatched, approximately 400 actively swimming larvae were transferred to two beakers (5L). Each beaker contained similar number of larvae, with aerated seawater maintained at a temperature of 23 ± 1°C and a 12:12 hour photoperiod. Specimens of each zoeal stage were collected after the larvae moulted and preserved in a 70% ethylene glycol solution. At least two larvae from each stage were dissected and examined on glass slides under a stereo microscope (OLYMPUS SZX12) using fine entomological needles. Appendages were drawn using a camera lucida installed on a compound microscope (Olympus BX50). The descriptions and figures are arranged according to the standards proposed by
Zoea I (Fig.
Period from hatching to the end of the instar: 1–8 days.
Size (n = 5): CL, 0.40 mm (0.38–0.42 mm); BL, 2.28 mm (2.27–2.30 mm); TL, 2.87 mm (2.82–2.90 mm).
Carapace (Fig.
Antennule (Fig.
Antenna (Fig.
Mandible (Fig.
Maxillule (Fig.
Maxilla (Fig.
First maxilliped (Fig.
Second maxilliped (Fig.
Third maxilliped (Fig.
Pereiopods absent.
Pleon (Fig.
Pleopods absent.
Uropods absent.
Telson (Fig.
Zoea II (Fig.
Period from hatching to the end of the instar: 8–12 days.
Size (n = 4): CL, 0.45 mm (0.43–0.48 mm); BL, 2.43 mm (2.41–2.44 mm); TL, 2.98 mm (2.96–3.01 mm).
Carapace (Fig.
Antennule (Fig.
Antenna (Fig.
Mandible (Fig.
Maxillule (Fig.
Maxilla (Fig.
First maxilliped (Fig.
Second maxilliped (Fig.
Third maxilliped (Fig.
Pereiopods absent.
Pleon (Fig.
Pleopods absent.
Uropod absent.
Telson (Fig.
Zoea III (Fig.
Period from hatching to the end of the instar: 12–17 days.
Size (n = 3): CL, 0.52 mm (0.50–0.55 mm); BL, 2.45 mm (2.39–2.53 mm); TL, 2.94 mm (2.81–3.08 mm).
Carapace (Fig.
Antennule (Fig.
Antenna (Fig.
Mandible (Fig.
Maxillule (Fig.
Maxilla (Fig.
First maxilliped (Fig.
Second maxilliped (Fig.
Third maxilliped (Fig.
Pereiopods (Fig.
Pleon (Fig.
Pleopods absent.
Uropod (Fig.
Telson (Fig.
Zoea IV (Fig.
Period from hatching to the end of the instar: 17–21 days.
Size (n = 2): CL, 0.56 mm (0.54–0.58 mm); BL, 3.03 mm (2.98–3.07 mm); TL, 3.26 mm (3.25–3.26 mm).
Carapace (Fig.
Antennule (Fig.
Antenna (Fig.
Mandible (Fig.
Maxillule (Fig.
Maxilla (Fig.
First maxilliped (Fig.
Second maxilliped (Fig.
Third maxilliped (Fig.
Pereiopods (Fig.
Pleon (Fig.
Pleopods absent.
Uropod (Fig.
Telson (Fig.
Zoea V (Fig.
Period from hatching to the end of the instar: 21–23 days.
Zoea V of Plesionika grandis, A dorsal view B carapace lateral view C pleon lateral view D anteroventral margin of carapace E antennule F antenna G mandible H maxillule I maxilla J first maxilliped K second maxilliped L third maxilliped M first pereiopod N second pereiopod O ventral view of anal spine.
Size (n = 3): CL, 0.61 mm (0.59–0.62 mm); BL, 3.05 mm (3.00–3.11 mm); TL, 3.25 mm (3.22–3.29 mm).
Carapace (Fig.
Antennule (Fig.
Antenna (Fig.
Mandible (Fig.
Maxillule (Fig.
Maxilla (Fig.
First maxilliped (Fig.
Second maxilliped (Fig.
Third maxilliped (Fig.
First pereiopod (Fig.
Second pereiopod (Fig.
Third, fourth, and fifth pereiopods absent.
Pleon (Fig.
Pleopods absent.
Uropod (Fig.
Telson (Fig.
Zoea VI (Fig.
Period from hatching to the end of the instar: 23–29 days.
Zoea VI of Plesionika grandis, A dorsal view B carapace lateral view C pleon lateral view D anteroventral margin of carapace E antennule F antenna G mandible H maxillule I maxilla J first maxilliped K second maxilliped L third maxilliped M first pereiopod N second pereiopod O third pereiopod P ventral view of anal spine.
Size (n = 2): CL, 0.62 mm (0.60–0.65 mm); BL, 3.07 mm (3.04–3.10 mm); TL, 3.26 mm (3.22–3.30 mm).
Carapace (Fig.
Antennule (Fig.
Antenna (Fig.
Mandible (Fig.
Maxillule (Fig.
Maxilla (Fig.
First maxilliped (Fig.
Second maxilliped (Fig.
Third maxilliped (Fig.
First pereiopod (Fig.
Second pereiopod (Fig.
Third pereiopod (Fig.
Fourth and fifth pereiopods absent.
Pleon (Fig.
Pleopods absent.
Uropod (Fig.
Telson (Fig.
Zoea VII (Fig.
Period from hatching to the end of the instar: 29–36 days.
Zoea VII of Plesionika grandis, A dorsal view B carapace lateral view C pleon lateral view D anteroventral margin of carapace E antennule F antenna G mandible H maxillule I maxilla J first maxilliped K second maxilliped L third maxilliped M first pereiopod N second pereiopod O third pereiopod P fourth pereiopod Q ventral view of anal spine.
Size (n = 2): CL, 0.68 mm (0.64–0.72 mm); BL, 3.75 mm (3.40–4.10 mm); TL, 3.98 mm (3.62–4.34 mm).
Carapace (Fig.
Antennule (Fig.
Antenna (Fig.
Mandible (Fig.
Maxillule (Fig.
Maxilla (Fig.
First maxilliped (Fig.
Second maxilliped (Fig.
Third maxilliped (Fig.
First pereiopod (Fig.
Second pereiopod (Fig.
Third pereiopod (Fig.
Fourth pereiopod (Fig.
Fifth pereiopod absent.
Pleon (Fig.
Pleopods absent.
Uropod (Fig.
Telson (Fig.
Zoea VIII (Figs
Period from hatching to the end of the instar: 36 days.
Size (n = 3): CL, 0.84 mm (0.80–0.92 mm); BL, 4.16 mm (3.88–4.37 mm); TL, 4.36 mm (4.06–4.55 mm).
Carapace (Fig.
Antennule (Fig.
Antenna (Fig.
Mandible (Fig.
Maxillule (Fig.
Maxilla (Fig.
First maxilliped (Fig.
Second maxilliped (Fig.
Third maxilliped (Fig.
First pereiopod (Fig.
Second pereiopod (Fig.
Third pereiopod (Fig.
Fourth pereiopod (Fig.
Fifth pereiopod absent.
Pleon (Fig.
Pleopods absent.
Uropod (Fig.
Telson (Fig.
The first eight zoeal stages of Plesionika grandis were obtained in 36 days after hatching, representing the longest larval rearing record for the genus. Previous longest larval culture for Plesionika shrimps was P. edwardsii by
Features of each larval stage as well as changes in appendage setation and setal types in P. grandis are summarized in Table
Characteristics of the zoeal stage of Plesionika grandis. a, aesthetasc; b, basal spine; c, cuspidate seta; d, distolateral seta; s, simple seta; spi, spiniform seta; p, plumose seta; spa, spatulate seta; st, strong seta; sl, slender spine.
Z1 | Z2 | Z3 | Z4 | Z5 | Z6 | Z7 | Z8 | |
---|---|---|---|---|---|---|---|---|
Duration (days) | 1-8 | 8-12 | 12-17 | 17-21 | 21-23 | 23-29 | 29-36 | 36 |
Carapace length (mm) | 0.40 | 0.45 | 0.52 | 0.56 | 0.61 | 0.62 | 0.68 | 0.84 |
Anterolateral spines | 3 | 3 | 4 | 4 | 4 | 7 | 7 | 7 |
Antennule | ||||||||
Peduncle | 1 tubercle | 2p | 5p,6p+2s | 1spi+4p,5p,6p+2s | 1spi+8p,5p,8p+2s | 1spi+10p,5p,8p+2s | 1spi+13p,5p,8p+2s | 1spi+15p,5p,8p+2s |
Endopod | 1d | 1p | 1p | 1p | 1p | 1p | 1p | 1p |
Exopod | 3a+1d+1s | 4a+1s+1spa | 2a+1p+1s | 2a+2p | 2a+2p | 2a+2p | 2a+2p | 2a+2p |
Antenna | ||||||||
Peduncle | 1b | 1b | 1b | 1b | 1b | 2b | 2b | 2b |
Endopod | 1p+1sl | 1p+1sl | 1spi+1s | 1spi | 0,0,4 | 0,0,0,1,5 | 0,0,1,0,1,1,1,5 | 0,0,0,0,1,0,1,1,0,0,0,0,0,0,0,0,1,2 |
Exopod | 11p+1d | 11p+1d | 12p+1d | 13p+1p | 14p+1p | 16p+1p | 17p+1p+2s | 20p+1p+4s |
Maxillule | ||||||||
Coxal endite setation | 2s+5p | 2s+5p | 2s+5p | 2s+5p | 3s+5p | 8p | 8p | 8p |
Basial endite setation | 2st+3c | 4st+3c | 4st+3c | 4st+3c | 4st+3c | 4st+3c | 4st+3c | 4st+3c |
Endopod setation | 1s+5p | 1s+5p | 1s+5p | 1s+5p | 1s+5p | 1s+5p | 1s+5p | 1s+5p |
Exopod setation | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Maxilla | ||||||||
Coxal endite setation | 9p+4p | 10p+4p | 10p+4p | 10p+4p | 10p+4p | 10p+4p | 10p+4p | 10p+4p |
Basial endite setation | 4p+4p | 4p+4p | 4p+4p | 4p+4p | 4p+4p | 4p+4p | 4p+4p | 4p+4p |
Endopod setation | 3+2+1+1+2 | 3+2+1+1+2 | 3+2+1+1+2 | 3+2+1+1+2 | 3+2+1+1+2 | 3+2+1+1+2 | 3+2+1+1+2 | 3+2+1+1+2 |
Exopod setation | 5p | 5p | 6p | 6p | 8p | 8p | 8p | 13p |
First Maxilliped | ||||||||
Coxal endite setation | 3p | 4p | 4p | 4p | 4p | 4p | 4p | 4p |
Basis endite setation | 12p | 12p | 12p | 12p | 12p | 12p | 12p | 12p |
Endopod setation | 3,1,2,4 | 3,1,2,4 | 3,1,2,4 | 3,1,2,4 | 3,1,2,4 | 3,1,2,4 | 3,1,2,4 | 3,1,2,4 |
Exopod setation | 4p | 5p | 5p | 5p | 5p | 5p | 5p | 5p |
Second Maxilliped | ||||||||
Coxal endite setation | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Basis endite setation | 9p | 9p | 9p | 9p | 9p | 9p | 9p | 9p |
Endopod setation | 3,1,2,5 | 3,1,0,2,5 | 3,1,0,2,5 | 3,1,0,2,5 | 3,1,0,2,5 | 3,1,0,2,5 | 3,1,0,2,6 | 3,1,0,2,6 |
Exopod setation | 5p | 6p | 6p | 6p | 6p | 6p | 6p | 6p |
Third Maxilliped | ||||||||
Coxal endite setation | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Basis endite setation | 3p | 4p | 4p | 4p | 4p | 4p | 4p | 4p |
Endopod setation | 2,1,2,4 | 2,1,0,2,4 | 2,1,0,2,5 | 2,1,0,2,5 | 2,1,2,4,5 | 2,2,2,4,5 | 2,2,2,4,4 | 2,2,2,6,4 |
Exopod setation | 5p | 6p | 7p | 7p | 8p | 8p | 8p | 9p |
The early zoeal morphology of P. grandis has the common characters of pandalid larvae, such as eye peduncle narrowed at base, carapace with two dorsal protuberances and anteroventral margin bearing spines, antennule with peduncle strongly concave and exopod bearing spatulate seta, antenna with segmented exopod, rostrum elongated in earlier stages (see
(1) Number of spines on anteroventral margin of carapace: P. edwardsii with two spines in ZI, but disappeared in ZII and later stages; P. narval with three spines in ZI to ZV; P. grandis with three spines in ZI, increased to four spines in ZIII, and then, seven spines in ZVI.
(2) Number of tubercles on antennule in ZI: P. edwardsii and P. narval with two tubercles, P. grandis with one.
(3) Endopod segmentation of antenna: P. grandis 3-segmented in ZV, 5-segmented in ZVI, 8-segmented in ZVII, 18-segmented in ZVIII; P. edwardsii segmented only in ZVII and 3-segmented; P. narval segmented since ZV and 2-segmented.
(4) Third maxilliped setation in ZI: Basis with three setae in P. edwardsii and P. grandis, whilst P. narval with four setae. Moreoever, P. edwardsii has a somewhat different endopod setation at the third maxilliped (1, 1, 2, 4 vs. 2, 1, 2, 4 in the other two species).
Furthermore, the ZVII of P. grandis appeared to be more developed than that of P. edwardsii by having the first three pairs of pereiopods well developed (vs. only first two pereiopods well developed in the latter). This indicates that the larval development of P. edwardsii may have even longer duration. Although the numerous species in Plesionika are often separated into species groups (see
Species of Plesionika likely have very long larval development (see
Sincerely thanks are extending to the two reviewers J.M. Landeira and M. Terossi, and the subject editor S. De Grave, for their valuable suggestions and comments. This work was supported by grants from the Ministry of Science and Technology, Taiwan, R.O.C.